Add sendToDevice tests
Adds the test from tests/46direct/01directmessage.pl as well as two new tests to test that to-device messages are only delivered once and are ordered by arrival.
Federation tests are the same as the CS api tests.
@S7evinK I haven't (yet) reviewed this, but: we should remove the tests from Synapse at the same time as we add them to Complement, to avoid the having two copies of a test that get out of sync.
(This is a recent change: we discussed it in the Synapse team yesterday and we are now happy enough with our Complement coverage that we can start turning off Sytest tests.)
Looks like this has a conflict again. 😢 I'm assuming this is still in need of a review?
Closing as stale.