Add option to set max_receive_message_length in client config

[daikeshi]

Fixes #42

[hughmiao]

thanks for the PR, Keshi. some nit comments.

[hughmiao]

let's create a message, e.g., GrpcChannelArguments, and use that in the MetadataStoreClientConfig as well as the MetadataStoreServerConfig too. The server needs to be aware of argument as well, correct? also having a message, helps to extend to support other channel options. wdyt?

[hughmiao]

consider to build the custom server and try the client change to see whether this fixes your issue?

[daikeshi]

sounds good! @hughmiao, I'll work more on this PR later this week.

[daikeshi]

@hughmiao sorry for the delay. I added GrpcChannelArguments message to handle max_receive_message_length grpc option. MetadataStoreServerConfig should be fine since it's already been parsing grpc arguments (

ml-metadata/ml_metadata/metadata_store/metadata_store_server_main.cc

Line 238 in 5093603

AddGrpcChannelArgs(FLAGS_grpc_channel_arguments, &builder);

).

I also tested it locally and it worked as expected. Please take another look and let me know if it's good to go. Thank you!

In [1]: from ml_metadata.proto import metadata_store_pb2
   ...: import ml_metadata as mlmd
   ...: metadata_connection_config = metadata_store_pb2.MetadataStoreClientConfig()
   ...: metadata_connection_config.host = "127.0.0.1"
   ...: metadata_connection_config.port = 8080
   ...: metadata_connection_config.channel_arguments.max_receive_message_length = 0
   ...: store = mlmd.MetadataStore(metadata_connection_config)
   ...: store.get_artifact_types()
...
...
~/Projects/google/ml-metadata/ml_metadata/metadata_store/metadata_store.py in _call_method(self, method_name, request, response)
    172         # description.
    173         # https://grpc.github.io/grpc/python/_modules/grpc.html#StatusCode
--> 174         raise _make_exception(e.details(), e.code().value[0])  # pytype: disable=attribute-error
    175
    176   def _swig_call(self, method, request, response) -> None:

ResourceExhaustedError: Received message larger than max (3583 vs. 0)

[hughmiao]

thanks for the contribution, @daikeshi