* Revert "Revert "[App Net] Switch Router to Mesh and Add unique string to Scope (#28145)" (#28176)"
This reverts commit cc968b2158.
* Allow scope to be None
* Add back references and scope field
* Set scope in router
* Reverse order of cleanup
* Add router_scope flag
* Use router_scope flag to create Router
* I apparently don't know how to brain
* Yapf
* Yeah, that can't be the default
* Remove debug print
* Remove impossible todos
* And another
* Switch from router-scope to config-scope
* Implement schema changes
* Use backend service URL
* Use CLH reference format to backend service
* I am an idiot
* *internal screaming*
* Try project number
* Why is this all awful
* Go back to trying project name
* Try cleaning things up
* Agh
* Address review comments
* Remove superfluous Optional type