Fix #12308: Cannot use cheats in editor modes

[Gymnasiast]

This allows opening the cheats window while in editor mode. Some tabs and options are disabled because they are not relevant to these modes.

[AaronVanGeffen]

At the time of writing, the cheats window looks like this when opened in the scenario editor:

I don't like the tabs missing entirely. Perhaps they could be repositioned to fill the gap, but ideally, I would like this to use the disabled tab sprite introduced in #5138. With Twitch support removed, I believe no window is currently using it. However, I think it would be a perfect fit for this.

In #5138, the sprite on the widget definition itself was changed, depending on the compile-time availability of Twitch. I believe it would be easy to do something similar in the invalidate event instead.

A more appropriate solution would probably be to swap out the sprite in widget_tab_draw in Widget.cpp instead. While writing this, I realise this probably warrants a PR of its own. Perhaps along with the MakeTab abstraction I've been meaning to work on.

Just to illustrate, here's what the disabled Twitch tab looked like:

[Gymnasiast]

Since you said that handling greying out properly requires a PR of its own to do properly, I have opted for the simplest solution: updating the positions so that there is no awkward gap between tabs 1 and 4.

[AaronVanGeffen]

Repositioning the tabs should probably be a generic window function, but in its current state, this will do.

I will work on a PR that refactors the tab definitions soon-ish.