Allow for manual control of video call quality

### Your use case

#### What would you like to do?
I would like to be able to manually control the quality of a video call, similar to how the old app had the HD toggle, or how Discord offers the 4 option slider between the "best performance" and "best quality" extremes.

#### Why would you like to do it?
This is useful on slow or metered connections where a video call is still preferred over an audio call. It would be especially useful in calls with multiple participants.

#### How would you like to achieve it?
An HD toggle like in the old app or a 4 option slider like in Discord (off - low - standard - best). The setting should affect not just the amount of data the user sends but also receives, i.e. make everyone's video quality lower for me.

### Have you considered any alternatives?

A global setting like "switch to lower quality on metered connections" would be a reasonable alternative.

### Additional context

_No response_

### Are you willing to provide a PR?

No