Use AutoDiscovery.getRawClientConfig() instead of MatrixClient.getClientWellKnown() and wait for result

[hughns]

I'm very open to suggestions on what is sensible to test around this...

This is a second attempt at #2901

[fkwp]

I tested it on EX iOS nightlies -- and it works

[toger5]

This is quiet a big issue and very much in conflict with the mission that users should use their own SFU configured on their home servers, I think we really should merge this asap.
Otherwise all our communication that users should not rely on the config in EC is wrong if it does not work atm.

So I will approve this and merge it. But Will also open an issue that this migh be fixable with a underling race condition.

[toger5]

Maybe we want to do a check if the client already knows about the well known? so we save the http request in that case. I suspect this is a race condition since it worked at some point.
So maybe at some point this works again.

I also think however that we might want to get to the root of where this race condition occurs. And when we find it, we can use the old logic again.

Suggested change

	const wellKnownFoci = (await AutoDiscovery.getRawClientConfig(domain))?.[
	FOCI_WK_KEY
	];
	const wellKnownFoci = rtcSession.room.client.getClientWellKnown()?.[FOCI_WK_KEY] ? (await AutoDiscovery.getRawClientConfig(domain))?.[
	FOCI_WK_KEY
	];