KeybindsOptions: Default categories accessible outside of the state, translation support for custom options

[Bitto1070]

• Moved the categories outside the "create" function to let them become accessible to other states when KeybindsOptions is imported;
  • Theoretically, this shouldn't cause any issues, as it's not replacing the current categories variable.
• Added translation support to custom options;
  • It checks if the translation even exists first before translating, to not cause any issues with old options.xml files (hopefully).
• custom options menus are now tagged with a "custom: true", like their settings;
  • Really only used to check if it should add the "KeybindsOptions." prefix before translating. Might be useful to someone else, though.
    • oh yeah i also kinda removed that prefix from the translate function so people aren't forced to use it on their options.xml if they want to add translation support
• also makes isSubstate public

[HeroEyad]

this is very good, i like this.

[HeroEyad]

@NexIsDumb thoughts?