"a365 cleanup azure" does not delete Bot endpoint

[adner]

This message claims that the command a365 cleanup azure deletes the existing bot endpoint. This is however not the case, the CreateAzureCleanupCommand doesn't remove the Bot endpoint. It should probably call botconfigurator.DeleteEndpointWithAgentBlueprintAsync.

Also see #129, it might be better with a dedicated command for setting the bot endpoint, rather than it being part of a cleanup operation.

[pontemonti]

Triage:

1. We should have a command a365 cleanup blueprint --endpoint-only, to match a365 setup blueprint --endpoint-only
2. We need to update the error message to point to new command.