Do not close full image view on click on another screen while user have multiple displays setup

[the-stas]

Steps to reproduce

1. Setup a few displays for your computer.
2. Open some image in full screen mode.
3. Move focus to another screen.

Expected behaviour

On screen with telegram app with open image in full screen mode app state shouldn't change.

Actual behaviour

Image in full screen mode is closed.

Configuration

Operating system:

Version of Telegram Desktop:

Multiple display configuration:
At least two displays

[SnoElement]

Additional report from Telegram:
https://t.me/macswift/109047

If only we got the fix for full-screen media on multi-monitor setups.
Images and videos only open in full-screen on the main monitor, and if you keep the media open and switch to an app on the other monitor, the media closes and the whole app bugs out so you have to relaunch it.

This appears to be the same multi-monitor full-screen media viewer issue reported here, with an additional note that the app can get into a bad state requiring relaunch after the viewer closes unexpectedly.

Potential fix is in PR #1357.