The `send_messages` permission has been deprecated for use with
broadcast services, so we can drop support for it in the code. We
were supporting both the old permissions and new permissions
(`create_broadcasts` and `approve_broadcasts`) while we switched people
over.
This removes `send_messages` from the `user_has_permissions` decorator
around the broadcast routes and from the page to view a broadcast and
broadcast dashboards. We can now git rid of a lot of the parameterization
that was temporarily added to the tests.
8b08661902