Add protobuf formatter and linter

[li1234yun]

Add protobuf formatter

support protobuf auto format when user save file.

Add protobuf linter

Support google protobuf style

[alexolog]

protobuf formatting can be done by calling clang-format
protobuf linting can be done by calling protolint

[ytwanghaoyu]

+1 for this feature

[ytwanghaoyu]

https://github.com/protocolbuffers/txtpbfmt This project provide official support for formatting text proto. Will be perfect if you can merge this tool within your extension