Summary:
Adding the CGO interface and broker compiler api, but not implementing the
C++ side just yet.

Test Plan: bazel run //src/vizier/components:broker_compiler_go

Reviewers: zasgar, michelle, #engineering

Reviewed By: zasgar, #engineering

Differential Revision: https://phab.corp.pixielabs.ai/D602

GitOrigin-RevId: c9b66cc499c4895cce8c9c40e06b87110809d994