[client] Add dockerfile for client
[client] Add dockerfile for client

This aleviates the trouble community members have been having with
dependency management, especially with regards to protobuf.

aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra