Added "Quit Application" button to pause menu. Set menus to disabled by default if they got disabled by default

Couldn't bear the visual clutter in the editor, and having to go back to the launch menu.
Opening those prefabs caused Unity to change a whole lot of other prefabs and assets as well. At least some of those changes are strings getting surrounded by quotes, but for most others I have to guess option names changed in Unity 6. Gonna commit all at once, because I don't want to accidentally break something if a specific combination of changes shouldn't work.

CheckServer.cs got completely redundant and thus removed. This includes the "empty_CheckServer" Game objects in the shrink_menu prefabs

CommunicationEvents now has an Enum for the ServerSlots and a Dictionary to get their data. This e.g. allows iterating over all slots and thus CheckServer is nearly empty now. Most of the other files just had the references adapted.

There seemed to be no use of IPcheckGeneration, as it got decreased if it was to high.

fix browser scrollbars and reduce page scale from 4 to 3 to make it less likely for scrollbars to appear

This reverts commit 03b32df1.

This reverts commit c6499889.