Moniker streaming functions return standard reponse message instead of custom data type

[doshirohan]

What does this Pull Request accomplish?

• Values returned from streaming APIs are now in <function-name>StreamingResponse message.
• Most of the custom codegen written for Moniker APIs was needed because output was not in standard "response" message. With this change, I was able to delete most of the custom codegen written for streaming functionality.

Why should this Pull Request be merged?

Moniker functions used for streaming data to/from clients used to return custom data types defined in custom_proto.mako file for DAQ and FPGA. This has multiple limitations.

• The custom types had only one field value for streaming. Read APIs with multiple out parameters need multiple values in response.
• Response was not provided in standard <function-name>Response message that other grpc APIs use.

What testing has been done?

• Existing integration tests for FPGA streaming APIs pass.
• Executed sample client tests with StreamRead/StreamWrite and validated results.