Allow selecting "prejoin" events by state keys (#14642)

* Declare new config

* Parse new config

* Read new config

* Don't use trial/our TestCase where it's not needed

Before:

```
$ time trial tests/events/test_utils.py > /dev/null

real	0m2.277s
user	0m2.186s
sys	0m0.083s
```

After:
```
$ time trial tests/events/test_utils.py > /dev/null

real	0m0.566s
user	0m0.508s
sys	0m0.056s
```

* Helper to upsert to event fields

without exceeding size limits.

* Use helper when adding invite/knock state

Now that we allow admins to include events in prejoin room state with
arbitrary state keys, be a good Matrix citizen and ensure they don't
accidentally create an oversized event.

* Changelog

* Move StateFilter tests

should have done this in #14668

* Add extra methods to StateFilter

* Use StateFilter

* Ensure test file enforces typed defs; alphabetise

* Workaround surprising get_current_state_ids

* Whoops, fix mypy

1 files changed, 9 insertions, 3 deletions

diff --git a/mypy.ini b/mypy.ini

index 727536df50..37acf589c9 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -89,6 +89,12 @@ disallow_untyped_defs = False
 [mypy-tests.*]
 disallow_untyped_defs = False
 
+[mypy-tests.config.test_api]
+disallow_untyped_defs = True
+
+[mypy-tests.federation.transport.test_client]
+disallow_untyped_defs = True
+
 [mypy-tests.handlers.test_sso]
 disallow_untyped_defs = True
 
@@ -101,7 +107,7 @@ disallow_untyped_defs = True
 [mypy-tests.push.test_bulk_push_rule_evaluator]
 disallow_untyped_defs = True
 
-[mypy-tests.test_server]
+[mypy-tests.rest.*]
 disallow_untyped_defs = True
 
 [mypy-tests.state.test_profile]
@@ -110,10 +116,10 @@ disallow_untyped_defs = True
 [mypy-tests.storage.*]
 disallow_untyped_defs = True
 
-[mypy-tests.rest.*]
+[mypy-tests.test_server]
 disallow_untyped_defs = True
 
-[mypy-tests.federation.transport.test_client]
+[mypy-tests.types.*]
 disallow_untyped_defs = True
 
 [mypy-tests.util.caches.*]