- Add a new widget type for input and extend it from other input widgets
- Add a new label type that can be linked to an input widget
- Change the label color when the input's disabled state changes
- Add a property for arrows image collection (in drop-downs, scrollbars
and production tabs)
- Add a property for separators image collection (in drop-downs)
- Add hover and disable states to the drop-down separator
- Unify button, textfield and checkbox state suffixes
* Add HotkeyDialogLogic.cs
* Add dialog-hotkey.yaml to all mods
* Add `GetFirstDuplicate` method to HotkeyManager to aid in validation
* Add "Player" and/or "Spectator" type to all hotkeys to allow for
validation based on overlapping types
* Change settings.yaml and SettingsLogic.cs to work with the new dialog
