The 'connecting' tile change meant that we could have tiles right
at the start of the call where we wouldn't have before, and in fact
could have tiles for other users before we even had a tile for ourself.
This threw off the logic for ordering tiles which had a special case
for 1:1 calling which assumed that one of the tiles in a 1:1 call was
the local user. In this case, this assumption wasn't true at the very
start of the call, so the tile orders got assigned incorrectly and then
persisted for the rest of the call.
Fixes https://github.com/vector-im/element-call/issues/694
* Make the embedded mode screen sharing a request-each-way rather
than request-and-reply, since replies time out and so can't wait
for the user.
* Try normal screen sharing first, then fall back to using the widget
API if it fails (for lack of a good way of detecting when we
should be using the widget API).
Fixes https://github.com/vector-im/element-call/issues/649
This will probably be overly sensitive until we start timing out
member events (ie. https://github.com/matrix-org/matrix-js-sdk/pull/2446
lands) because lots of calls might have old member events from people
who've joined previously.
