Remove config.Config from remote package

As we are ready to get rid of the global config.Config variable this change does exact it for the files in the remote package. It also includes some small refactoring like adding setup functions, renames, marking functions as test-helpers, etc. The tests dependent on usage of the ruby-sidecar assembled into a single TestWithRubySidecar test and runs as separate sub-tests re-using the same ruby-sidecar instance.

The ListenGitalySSHCalls function used only in one place so we move it closer to where it is used. It is refactored to depend on passed in config.Cfg parameter and doesn't return it back anymore.

Part of: #2699 (closed)