Refactor PersistentWindowSettings and persist window minimized state

[falbrechtskirchinger]

• Remove unneeded PersistentWindowSettings constructors and move default initialization in class.
• Look up PersistentWindowSettings only once in IngameWindow (assumes pointer stability). This will make more of a difference when more settings are saved in these PRs:
  • Improve in-game window positioning #1601
  • Allow excluding windows from being closed via Escape key #1606
• Save and restore the minimized state of in-game windows. This required some more changes to avoid calling unqualified virtual Resize() from the constructor.

[Flamefire]

Any chance you can come up with a test especially for the minimized state restore? Should be enough to use a dummy window with a CGI ID matching an "enabled" window

Just want to be sure we'd catch e.g. the virtual call bug in the ctor you found.

[falbrechtskirchinger]

Any chance you can come up with a test especially for the minimized state restore? Should be enough to use a dummy window with a CGI ID matching an "enabled" window

Done. Let me know if this is what you had in mind.

Just want to be sure we'd catch e.g. the virtual call bug in the ctor you found.

That's rather difficult to test. I couldn't call SetMinimized() from the constructor, because that ultimately calls Resize(), and clang-tidy would rightfully warn, that this doesn't call the most derived Resize() as one might expect/want.
Instead, I'm calling Window::Resize() myself, which is already called from the constructor, so I wouldn't expect any unanticipated side effects.

[falbrechtskirchinger]

@Flamefire Rebased and resolved the one-line merge conflict in IngameWindow.h. You can re-enable auto-merge.