Merge changes from topic "refactor-pac" into main

* changes:
  Update unit tests to reflect the changes to RoutingCoordinator and PrivateAddressCoordinator
  Move PrivateAddressCoordinator from Tethering to staticlibs
  Refator IpServer to allocate IPv4 address via RoutingCoordinatorManager API
  Introduce PrivateAddressCoordinator methods at RoutingCoordinatorManager