Assert current thread in ESQL

This change adds more assertions for current thread in ESQL

Author: idegtiarenko

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/session/EsqlSession.java

@@ -365,6 +365,7 @@ public void analyzedPlan(
         QueryBuilder requestFilter,
         ActionListener<LogicalPlan> logicalPlanListener
     ) {
+        assert ThreadPool.assertCurrentThreadPool(ThreadPool.Names.SEARCH);
         if (parsed.analyzed()) {
             logicalPlanListener.onResponse(parsed);
             return;
@@ -448,6 +449,11 @@ private void preAnalyzeLookupIndex(
         String localPattern = lookupIndexPattern.indexPattern();
         assert RemoteClusterAware.isRemoteIndexName(localPattern) == false
             : "Lookup index name should not include remote, but got: " + localPattern;
+        assert ThreadPool.assertCurrentThreadPool(
+            ThreadPool.Names.SEARCH,
+            ThreadPool.Names.SEARCH_COORDINATION,
+            ThreadPool.Names.SYSTEM_READ
+        );
         Set<String> fieldNames = result.wildcardJoinIndices().contains(localPattern) ? IndexResolver.ALL_FIELDS : result.fieldNames;
 
         String patternWithRemotes;
@@ -633,6 +639,11 @@ private void preAnalyzeMainIndices(
         QueryBuilder requestFilter,
         ActionListener<PreAnalysisResult> listener
     ) {
+        assert ThreadPool.assertCurrentThreadPool(
+            ThreadPool.Names.SEARCH,
+            ThreadPool.Names.SEARCH_COORDINATION,
+            ThreadPool.Names.SYSTEM_READ
+        );
         // TODO we plan to support joins in the future when possible, but for now we'll just fail early if we see one
         List<IndexPattern> indices = preAnalysis.indices;
         if (indices.size() > 1) {