rest-api-spec: fix type of enums (elastic#137521)

Sometimes enums are comma-separated, in which cases they are lists with
options. In other cases, they were specified as string without options, which
was incorrect.

(cherry picked from commit 8acc4d1)

# Conflicts:
#	rest-api-spec/src/main/resources/rest-api-spec/api/indices.resolve_index.json
#	rest-api-spec/src/main/resources/rest-api-spec/api/indices.unfreeze.json
#	rest-api-spec/src/main/resources/rest-api-spec/api/inference.put_ai21.json
#	rest-api-spec/src/main/resources/rest-api-spec/api/inference.put_contextualai.json
#	rest-api-spec/src/main/resources/rest-api-spec/api/inference.put_llama.json

Author: pquentin

rest-api-spec/src/main/resources/rest-api-spec/api/async_search.submit.json

@@ -117,7 +117,7 @@
         "description": "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified)"
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/cat.aliases.json

@@ -63,7 +63,7 @@
         "default": false
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/cat.indices.json

@@ -108,7 +108,7 @@
         "default": false
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/cat.segments.json

@@ -110,7 +110,7 @@
         "description": "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified). Only allowed when providing an index expression."
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/cluster.health.json

@@ -35,7 +35,7 @@
     },
     "params": {
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/cluster.state.json

@@ -104,7 +104,7 @@
         "description": "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified)"
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/count.json

@@ -55,7 +55,7 @@
         "description": "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified)"
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/delete_by_query.json

@@ -78,7 +78,7 @@
         "description": "What to do when the delete by query hits version conflicts?"
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/eql.search.json

@@ -72,7 +72,7 @@
         "description": "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified)"
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",

rest-api-spec/src/main/resources/rest-api-spec/api/field_caps.json

@@ -54,7 +54,7 @@
         "description": "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified)"
       },
       "expand_wildcards": {
-        "type": "enum",
+        "type": "list",
         "options": [
           "open",
           "closed",