/sync is not bundling aggregations for limited rooms

[clokep]

MSC2675 says that /sync is one of the APIs which should bundle aggregations:

GET /sync, only for room sections in the response where limited field is true; this amounts to all rooms in the response if the since request parameter was not passed, also known as an initial sync.

Currently it always disables bundled aggregations for this endpoint, see #5220.

We should also double check the other endpoints:

• GET /rooms/{roomId}/messages -- see code
• GET /rooms/{roomId}/context -- see code (note that this doesn't bundle them for state events, unclear if this is "fine" or not)
• GET /rooms/{roomId}/event/{eventId} -- see code
• GET /sync
• GET /relations -- see Include bundled events when requesting relations #11087

[germain-gg]

Blocks element-hq/element-web#19588

[germain-gg]

From my tests on vector.modular.im it appears that GET /rooms/{roomId}/event/{eventId} includes the bundled relationship correctly

[clokep]

It looks like we include them in all the other places, minus the state events when calling context.

[clokep]

Reopening due to #11583.