Add tooltips for join-queue and leave-queue and use them in non-singleplayer rooms

[AntlerForce]

Also do not say $leaveq in singleplayer games.

[FIr3baL]

• looks good to me
• this PR is extending Play/Spectate button reactions correctly for singleplayer games, which i never test that much, thank you :)
• tested with singleplayer and multiplayer

I´ll make some follow-up changes:

1. in multiplayer the "play"-button not necessary stands for "join-queue" - but only, when all teams are full, otherwise it´s a real play-button
2. Nothing to do with this PR, but Play button should become "active", when we are on queue, because more "play" is not possible than being in the join-queue already; currently the play button becomes active, when we really got a seat in the playerlist

[FIr3baL]

And i wasn't aware, that i'm using the wrong apostrophe for english all the time. On german keyboard we can access the "acute, backtick or left quote" [´] directly, while the apostrophe ['] needs Shift+#
Lessons learned :)