Problem

In current dev builds, if you turn on automatic registry refreshing at launch in the settings, you can sometimes end up with the main menu disabled and the close button not working at startup.

Causes

• In Many improvements for failed downloads #3635 and Update mod list through Wait.StartWaiting #3637 we tried to improve the Wait tab's encapsulation and how it's used, and some of those updates must have created a state where we disable the window and don't re-enable it, but I have not been able to pin down exactly how it happened.
• Main.SwitchEnabledState is a toggle that keeps state in a private _enabled variable, but every place that calls it wants specifically to either enable or disable the window; there is no point where a toggle actually makes sense like it does with a checkbox. If that state gets out of sync unexpectedly, then those calls all flip, we disable when we mean to enable and vice versa, and we end up with a disabled window that can't be re-enabled.
  • Some places use Main.SwitchEnabledState and some enable or disable without it, which would be a great way for _enabled to get out of sync

Changes

• Main.SwitchEnabledState from MainRepo.cs is split into Main.EnableMainWindow and Main.DisableMainWindow in Main.cs, and all calling code is updated to use the right one based on what is being done at that point
• Every other place that I could find that enables or disables the tabs and menus is also updated to use Main.EnableMainWindow and Main.DisableMainWindow
• The unused parameter of Wait.Finish and HideWaitDialog is removed

This fixes the bug and should help keep things more consistent in the future.