[services] Backup - Connect to Blob - Compile protos

Summary:
Depends on D4888

I added the code that compiles proto files. We need to compile the blob proto file in order to write a client that will communicate with the service.

Test Plan: backup still builds

Reviewers: varun, max, tomek, ashoat, jon

Reviewed By: varun, tomek, ashoat, jon

Subscribers: jon, ashoat, tomek, atul, abosh

Differential Revision: https://phab.comm.dev/D4889