Refactor scope to support type of all in GitClassProxy

The following discussion from !116949 (merged) should be addressed:

• @terrichu started a discussion:

  issue (non-blocking): this will not work for when the type is set to all. I know that isn't used in the codebase but this should be refactored to cover for when the type is set to all (and can be done in a follow up). I'll create a follow up and one of us can grab it for %16.1