Yellow squiggly lines begone!
Done automatically on .cpp files through `run-clang-tidy`, with manual corrections to the mistakes.
If an import is directly used, but is technically unnecessary since it's recursively imported by something else, it is *not* removed.
The tool doesn't touch .h files, so I did some of them by hand while fixing errors due to old recursive imports.
Not everything is removed, but the cleanup should be substantial enough.
Because this done on Linux, code that isn't used on it is mostly untouched.
(Hopefully no open PR is depending on these imports...)

The names attached to the BadgeStatus object are obsolete and unneeded and are removed from everything that uses them. All BadgeStatus references are updated to just Badge.

Achievement badges/icons are refactored into the type CustomTextureData::ArraySlice::Level as that is the data type images loaded from the filesystem will be. This includes everything that uses the badges in the Qt UI and OnScreenDisplay, and similarly removes the OSD::Icon type because Level already contains that information.

Was informed by the RetroAchievements team that this isn't an option in most emulators, and as the next commits will be to enable default icons, there will always be something to display.

If achievements were disabled but a player token is in settings, prior to this change the Achievement Manager dialog would show a box with no player name and score zero, which is unnecessary.

The RetroAchievements client object now handles these three settings as a singular "spectator" mode that will be added in a future commit.