Create repo for proto file and setup CI

[pragnagopa]

• Proto file needs to be moved to it's repo
• Setup CI
• Update Javascript and Java worker to pull proto files from the new repo.

• Create repo (Done: https://github.com/Azure/azure-functions-language-worker-protobuf)
• PR out for protobuf
• Create release on protobuf repo
• Move script to download the protobuf release (Consume proto file repo and add enableContentNegotiation #2696)
• Move Node to download the protobuf release (Consume .proto file from separate repo and reflect enableContentNegotiation change azure-functions-nodejs-worker#59)
• Move Java to download the protobuf release
• Move Python to download the protobuf release (Import FunctionRpc.proto as a subtree its repo azure-functions-python-worker#101)
• Document the process for future language workers

[christopheranderson]

Moved to top comment