[formrecognizer] add copy tests for new features in v2.1 (#14987)

* add copy tests for new features in v2.1

* rerecord test

* test that submodels are the same and fix get custom model for composed model

sdk/formrecognizer/azure-ai-formrecognizer/azure/ai/formrecognizer/_form_training_client.py

@@ -282,6 +282,8 @@ def get_custom_model(self, model_id, **kwargs):
             raise ValueError("model_id cannot be None or empty.")
 
         response = self._client.get_custom_model(model_id=model_id, include_keys=True, **kwargs)
+        if hasattr(response, "composed_train_results") and response.composed_train_results:
+            return CustomFormModel._from_generated_composed(response)
         return CustomFormModel._from_generated(response, api_version=self.api_version)
 
     @distributed_trace

sdk/formrecognizer/azure-ai-formrecognizer/azure/ai/formrecognizer/aio/_form_training_client_async.py

@@ -287,6 +287,8 @@ async def get_custom_model(self, model_id: str, **kwargs: Any) -> CustomFormMode
         response = await self._client.get_custom_model(
             model_id=model_id, include_keys=True, **kwargs
         )
+        if hasattr(response, "composed_train_results") and response.composed_train_results:
+            return CustomFormModel._from_generated_composed(response)
         return CustomFormModel._from_generated(response, api_version=self.api_version)
 
     @distributed_trace_async