This is some odds and ends found during the review of #11791
and while continuing to work in this code:
* Return attrs classes instead of dictionaries from some methods
to improve type safety.
* Call `get_bundled_aggregations` fewer times.
* Adds a missing assertion in the tests.
* Do not return empty bundled aggregations for an event (preferring
to not include the bundle at all, as the docstring states).
This makes the serialization of events synchronous (and it no
longer access the database), but we must manually calculate and
provide the bundled aggregations.
Overall this should cause no change in behavior, but is prep work
for other improvements.
Adds validation to the Client-Server API to ensure that
the potential thread head does not relate to another event
already. This results in not allowing a thread to "fork" into
other threads.
If the target event is unknown for some reason (maybe it isn't
visible to your homeserver), but is the target of other events
it is assumed that the thread can be created from it. Otherwise,
it is rejected as an unknown event.
Part of #9744
Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.
`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
