[ES|QL] Correct the lens_map_to_columns function call arguments (#213038)

## Summary

The else is being called atm only in Discover ES|QL mode, when the user
is typing stats or keep.
The `isTextBased` flag is missing which means that we don't call the
`mapToOriginalColumnsTextBased` but the one for the dsl mode which might
cause bugs.

I don't think that Peter had any reason to do so, it seems more as it
slipped.

x-pack/platform/plugins/shared/lens/public/datasources/text_based/to_expression.ts

@@ -122,6 +122,7 @@ function getExpressionForLayer(
           function: 'lens_map_to_columns',
           arguments: {
             idMap: [JSON.stringify(idMapper)],
+            isTextBased: [true],
           },
         },
         ...formatterOverrides,