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/http/federation/test_matrix_federation_agent.py

@@ -17,6 +17,7 @@ import logging
 from mock import Mock
 
 import treq
+from netaddr import IPSet
 from service_identity import VerificationError
 from zope.interface import implementer
 
@@ -103,6 +104,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
             reactor=self.reactor,
             tls_client_options_factory=self.tls_factory,
             user_agent="test-agent",  # Note that this is unused since _well_known_resolver is provided.
+            ip_blacklist=IPSet(),
             _srv_resolver=self.mock_resolver,
             _well_known_resolver=self.well_known_resolver,
         )
@@ -736,6 +738,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
             reactor=self.reactor,
             tls_client_options_factory=tls_factory,
             user_agent=b"test-agent",  # This is unused since _well_known_resolver is passed below.
+            ip_blacklist=IPSet(),
             _srv_resolver=self.mock_resolver,
             _well_known_resolver=WellKnownResolver(
                 self.reactor,