Replacing tower-grpc w/ Tonic

[tjtelan]

I rebased my master branch to the L11 master, because I am getting some really deeply confusing branch conflicts. I hope this will be the last 100+ commit diff, since my branch was only about 5 commits...

Closes #227 Fixes #229

[tjtelan]

I just cleaned up this PR. The files changed now accurately reflect the files I've changed.

In summary:

• Replace tower-grpc with tonic
• Clean up unused dependencies in all Cargo.toml
• Removed unnecessary clone of protobuf definitions for build.rs (tonic-build)
• Touch all of the protos to update the naming conventions (Including a workaround for #229)
• Update all of the grpc server/client stubs with their new names and async types, and added .await? in the BuildService subcommand_handler client/server stack
• Add .gitattributes to have Github ignore the legacy directory, so the project language becomes Rust