[TEST] Replace _source.mode with index.mapping.source.mode in integration tests - take 2 (#116072)

* Reapply "[TEST] Replace _source.mode with index.mapping.source.mode in integra…" (#116069)

This reverts commit e8bf344.

* [TEST] Replace _source.mode with index.mapping.source.mode in integration tests

* add reason

* add reason

* spotless

* revert unneeded

Author: kkrik-es

modules/aggregations/src/yamlRestTest/resources/rest-api-spec/test/aggregations/top_hits.yml

@@ -349,16 +349,17 @@ sequence number and primary term:
 ---
 synthetic _source:
   - requires:
-      cluster_features: ["gte_v8.4.0"]
-      reason: introduced in 8.4.0
+      cluster_features: ["mapper.source.mode_from_index_setting"]
+      reason: "Source mode configured through index setting"
 
   - do:
       indices.create:
         index: test_synthetic
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               page:
                 type: keyword

modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/50_script_doc_values.yml

@@ -1,4 +1,7 @@
 setup:
+  - requires:
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
   - do:
       indices.create:
         index: test
@@ -180,9 +183,9 @@ setup:
         body:
           settings:
             number_of_shards: 1
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               boolean:
                 type: boolean
@@ -5630,9 +5633,9 @@ version and sequence number synthetic _source:
         body:
           settings:
             number_of_shards: 1
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               keyword:
                 type: keyword

modules/mapper-extras/src/yamlRestTest/resources/rest-api-spec/test/match_only_text/10_basic.yml

@@ -278,16 +278,17 @@ setup:
 ---
 synthetic_source:
   - requires:
-      cluster_features: ["gte_v8.4.0"]
-      reason: synthetic source introduced in 8.4.0
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
 
   - do:
       indices.create:
         index: synthetic_source_test
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               foo:
                 type: match_only_text
@@ -355,16 +356,17 @@ tsdb:
 ---
 synthetic_source with copy_to:
   - requires:
-      cluster_features: ["mapper.source.synthetic_source_with_copy_to_and_doc_values_false"]
-      reason: requires copy_to support in synthetic source
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
 
   - do:
       indices.create:
         index: synthetic_source_test
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               foo:
                 type: match_only_text

modules/mapper-extras/src/yamlRestTest/resources/rest-api-spec/test/rank_feature/30_synthetic_source.yml

@@ -1,15 +1,16 @@
 setup:
   - requires:
-      cluster_features: ["mapper.source.synthetic_source_fallback"]
-      reason: introduced in 8.15.0
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
 
   - do:
       indices.create:
         index: test
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               pagerank:
                 type: rank_feature

modules/mapper-extras/src/yamlRestTest/resources/rest-api-spec/test/rank_features/20_synthetic_source.yml

@@ -1,15 +1,16 @@
 setup:
   - requires:
-      cluster_features: ["mapper.source.synthetic_source_fallback"]
-      reason: introduced in 8.15.0
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
 
   - do:
       indices.create:
         index: test
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               tags:
                 type: rank_features

modules/mapper-extras/src/yamlRestTest/resources/rest-api-spec/test/search-as-you-type/30_synthetic_source.yml

@@ -1,15 +1,16 @@
 setup:
   - requires:
-      cluster_features: ["mapper.track_ignored_source"]
-      reason: requires tracking ignored source
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
 
   - do:
       indices.create:
         index: test
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               a_field:
                 type: search_as_you_type

modules/mapper-extras/src/yamlRestTest/resources/rest-api-spec/test/token_count/10_basic.yml

@@ -36,15 +36,17 @@
 ---
 "Synthetic source":
   - requires:
-      cluster_features: ["mapper.track_ignored_source"]
-      reason: requires tracking ignored source
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
+
   - do:
       indices.create:
         index:  test
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               count:
                 type: token_count

modules/parent-join/src/yamlRestTest/resources/rest-api-spec/test/60_synthetic_source.yml

@@ -1,15 +1,16 @@
 supported:
   - requires:
-      cluster_features: ["mapper.source.synthetic_source_fallback"]
-      reason: introduced in 8.15.0
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
 
   - do:
       indices.create:
         index: test
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               join_field:
                 type: join

modules/percolator/src/yamlRestTest/resources/rest-api-spec/test/10_basic.yml

@@ -130,16 +130,17 @@
 ---
 "Synthetic source":
   - requires:
-      cluster_features: ["mapper.source.synthetic_source_fallback"]
-      reason: introduced in 8.15.0
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
 
   - do:
       indices.create:
         index: queries_index
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               query:
                 type: percolator

modules/reindex/src/yamlRestTest/resources/rest-api-spec/test/reindex/110_synthetic_source.yml

@@ -1,11 +1,16 @@
 setup:
+  - requires:
+      cluster_features: [ "mapper.source.mode_from_index_setting" ]
+      reason: "Source mode configured through index setting"
+
   - do:
       indices.create:
         index: synthetic
         body:
+          settings:
+            index:
+              mapping.source.mode: synthetic
           mappings:
-            _source:
-              mode: synthetic
             properties:
               kwd:
                 type: keyword