Expose ReceiverFetcher of power-dist results from PowerWrapper

This can be used in the BatteryPool that users can use to get a direct
stream of the power distributor results.

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

src/frequenz/sdk/microgrid/_power_wrapper.py

@@ -16,6 +16,8 @@
 # pylint: disable=cyclic-import
 from frequenz.client.microgrid import ComponentCategory, ComponentType
 
+from .._internal._channels import ReceiverFetcher
+
 # A number of imports had to be done inside functions where they are used, to break
 # import cycles.
 #
@@ -178,3 +180,7 @@ async def stop(self) -> None:
             await self._power_distributing_actor.stop()
         if self._power_managing_actor:
             await self._power_managing_actor.stop()
+
+    def distribution_results_fetcher(self) -> ReceiverFetcher[Result]:
+        """Return a fetcher for the power distribution results."""
+        return self._power_distribution_results_channel