Slim pause GUI

[elexis]

As mentioned in #1950, it would be nice to not have an overlay graying out the entire screen when someone else pauses, allowing the others to continue clicking on units and buildings, investigating what the allies and enemies are doing etc.

There should be a setting so that people can chose which variant to use, defaulting to the current one.

The pausing players can be shown in the topright corner where lagwarnings are also shown (see that removed TODO in the commit of #1950).

Notice players can technically still issue commands, which could probably be stopped by returning false from controlsPlayer if it's paused.

The current overlay might disable the camera hotkeys using #3676 since scrolling with the mouse is equally impossible.

[elexis]

The fundamental issue is that the overlay thing removes the ability to control anything in the session. It would also be good if the player could still select things after disconnect, open the chat history (with disabled or hidden controls), open the diplomacy screen and check the map.

[Vladislav Belov]

Isn't it unbalanced game for player who has paused it? Because all players could do something until paused player is absent (like make an useful queue of units or something else).

[elexis]

Allowing the non-pausing players to continue doing things meaningful to the match, besides chatting, while waiting for the pausing player(s) is the purpose of this feature. I don't mind if pausing is penalized.

[Imarok]

Move tickets to In-game UI as UI & Simulation got some sub components.