feat(ray): add protobuf for model and ray (#581)

Because
- We need to support Ray integration for our model service
- Ray uses specific protobuf definitions that need to be incorporated
- Some Ray protobuf files don't follow our standard naming conventions

This commit
- Adds protobuf definitions for Ray model service
- Configures `buf.yaml` to ignore Ray-specific protobuf files
- Enables comment-based lint ignores to handle Ray's non-standard naming
conventions

Author: pinglin

buf.yaml

@@ -16,9 +16,11 @@ lint:
     - PACKAGE_NO_IMPORT_CYCLE
   except:
     - FIELD_NOT_REQUIRED
+  ignore:
+    - model/model/v1alpha/model_ray_serve.proto # protobuf file copied from ray repo
   enum_zero_value_suffix: _UNSPECIFIED
   service_suffix: Service
-  disallow_comment_ignores: true
+  disallow_comment_ignores: false
 breaking:
   use:
     - FILE