Move originalTypes method to FieldAttribute

This moves originalTypes() from Attribute to FieldAttribute, since only
a FieldAttribute (and its subclasses) can refer to a field with multiple
types.

Author: bpintea

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/expression/Attribute.java

@@ -134,14 +134,4 @@ public String nodeString() {
     }
 
     protected abstract String label();
-
-    /**
-     * If this field is unsupported this contains the underlying ES types. If there
-     * is a type conflict this will have many elements, some or all of which may
-     * be actually supported types.
-     */
-    @Nullable
-    public List<String> originalTypes() {
-        return null;
-    }
 }

x-pack/plugin/esql-core/src/main/java/org/elasticsearch/xpack/esql/core/expression/FieldAttribute.java

@@ -20,6 +20,7 @@
 import org.elasticsearch.xpack.esql.core.util.PlanStreamOutput;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Objects;
 
 import static org.elasticsearch.xpack.esql.core.util.PlanStreamInput.readCachedStringWithVersionCheck;
@@ -242,4 +243,14 @@ protected String label() {
     public EsField field() {
         return field;
     }
+
+    /**
+     * If this field is unsupported this contains the underlying ES types. If there
+     * is a type conflict this will have many elements, some or all of which may
+     * be actually supported types.
+     */
+    @Nullable
+    public List<String> originalTypes() {
+        return null;
+    }
 }

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

@@ -43,6 +43,7 @@
 import org.elasticsearch.xpack.esql.action.EsqlQueryResponse;
 import org.elasticsearch.xpack.esql.action.EsqlQueryTask;
 import org.elasticsearch.xpack.esql.core.async.AsyncTaskManagementService;
+import org.elasticsearch.xpack.esql.core.expression.FieldAttribute;
 import org.elasticsearch.xpack.esql.core.expression.FoldContext;
 import org.elasticsearch.xpack.esql.enrich.AbstractLookupService;
 import org.elasticsearch.xpack.esql.enrich.EnrichLookupService;
@@ -321,12 +322,12 @@ private EsqlExecutionInfo createEsqlExecutionInfo(EsqlQueryRequest request) {
     private EsqlQueryResponse toResponse(Task task, EsqlQueryRequest request, Configuration configuration, Result result) {
         List<ColumnInfoImpl> columns = result.schema().stream().map(c -> {
             List<String> originalTypes;
-            if (c.originalTypes() == null) {
-                originalTypes = null;
-            } else {
+            if (c instanceof FieldAttribute fa && (originalTypes = fa.originalTypes()) != null) {
                 // Sort the original types so they are easier to test against and prettier.
-                originalTypes = new ArrayList<>(c.originalTypes());
+                originalTypes = new ArrayList<>(originalTypes);
                 Collections.sort(originalTypes);
+            } else {
+                originalTypes = null;
             }
             return new ColumnInfoImpl(c.name(), c.dataType().outputType(), originalTypes);
         }).toList();