Better UX with camera self-view in non-DM calls

### Your use case

#### What would you like to do?

See the view of my camera better

#### Why would you like to do it?

So that I'd understand what I'm actually showing

#### How would you like to achieve it?

There are plenty of ways, we might also have them all at the same time (@mxandreas PTAL):
1. Have a second permanent spotlight on top of the existing one, so that I would always see myself in the spotlight
2. See myself in the spotlight (currently I'm always locked to the first non-spotlight tile)
3. (I prefer this option) Be able to switch between fullscreen expanded tile view and the normal one in the portrait mode. This is currently possible only in the landscape mode.

### Have you considered any alternatives?

_No response_

### Additional context

I can provide the PR if you want