Change JSON Index column from ColumnReferenceExpression to Identifier type

Co-authored-by: llali <17187348+llali@users.noreply.github.com>

Author: Copilot

SqlScriptDom/Parser/TSql/Ast.xml

@@ -4603,7 +4603,7 @@
   <Class Name="CreateJsonIndexStatement" Base="IndexStatement" Summary="Represents the create JSON index statement.">
     <InheritedMember Name="Name" ContainerClass="IndexStatement" />
     <InheritedMember Name="OnName" ContainerClass="IndexStatement" />
-    <Member Name="JsonColumn" Type="ColumnReferenceExpression" Summary="The JSON column for the index."/>
+    <Member Name="JsonColumn" Type="Identifier" Summary="The JSON column for the index."/>
     <Member Name="ForJsonPaths" Type="StringLiteral" Collection="true" Summary="The JSON paths specified in the FOR clause. Optional may have zero elements."/>
     <InheritedMember Name="IndexOptions" ContainerClass="IndexStatement" />
     <Member Name="OnFileGroupOrPartitionScheme" Type="FileGroupOrPartitionScheme" Summary="The filegroup or partition scheme. Might be null."/>

SqlScriptDom/Parser/TSql/TSql170.g

@@ -16988,7 +16988,7 @@ createJsonIndexStatement [IToken tUnique, bool? isClustered] returns [CreateJson
 {
     Identifier vIdentifier;
     SchemaObjectName vSchemaObjectName;
-    ColumnReferenceExpression vJsonColumn;
+    Identifier vJsonColumn;
     FileGroupOrPartitionScheme vFileGroupOrPartitionScheme;
     StringLiteral vPath;
 
@@ -17010,7 +17010,7 @@ createJsonIndexStatement [IToken tUnique, bool? isClustered] returns [CreateJson
     {
         vResult.OnName = vSchemaObjectName;
     }
-    LeftParenthesis vJsonColumn=column tRParen:RightParenthesis
+    LeftParenthesis vJsonColumn=identifier tRParen:RightParenthesis
     {
         vResult.JsonColumn = vJsonColumn;
         UpdateTokenInfo(vResult, tRParen);