Apply an IP range blacklist to push and key revocation requests. (#8821)

Replaces the `federation_ip_range_blacklist` configuration setting with an
`ip_range_blacklist` setting with wider scope. It now applies to:

* Federation
* Identity servers
* Push notifications
* Checking key validitity for third-party invite events

The old `federation_ip_range_blacklist` setting is still honored if present, but
with reduced scope (it only applies to federation and identity servers).

tests/app/test_frontend_proxy.py

@@ -23,7 +23,7 @@ class FrontendProxyTests(HomeserverTestCase):
     def make_homeserver(self, reactor, clock):
 
         hs = self.setup_test_homeserver(
-            http_client=None, homeserver_to_use=GenericWorkerServer
+            federation_http_client=None, homeserver_to_use=GenericWorkerServer
         )
 
         return hs