feat: added prerelease commands and service defs to ruby client layer

[madhuravius]

This does populate the data for service_definitions:

service definitions:

prerelease_commands:

[shortcut-integration]

This pull request has been linked to:

• Shortcut Story #8853: Manage Services outside of Procfile
• Shortcut Story #9536: Manage before_release commands outside of .aptible.yml

[madhuravius]

This continues working without the endpoints (without erroring), so we should be free to merge:

To do the above, I redeployed the master branch and tested this repo's branch against master on my stack, showing that this is compatible without the backend changes deployed

[madhuravius]

validated one last time against my own sandboxes running master branch only (to ensure backwards compat)