Support Matrix v1.5

[clokep]

See https://matrix.org/blog/2022/11/17/matrix-v-1-5-release

Client-Server API

• Add m.reference relations, as per MSC3267.
• Add missing documentation for m.key.verification.request msgtype for in-room verification.

The other sections have no changes.

[clokep]

I think this just needs adding the numbers to the versions endpoint since Synapse already supports m.reference relations? Although IIRC the bundled format for m.reference got dropped, so we might want to update that at the same time?

[clokep]

Although IIRC the bundled format for m.reference got dropped, so we might want to update that at the same time?

It didn't get dropped, see here:

The aggregation format of m.reference relations consists of a single chunk property, which lists all the events which m.reference the event (the parent). Currently, only a single event_id field is present on the events in the chunk.

The thing we do "wrong" is generate pagination tokens and return those.

[clokep]

#14508 ended up dropping the unspecced fields.