- Change encoder position to 16-bit integer.
- Fix `SD_REPRINT_LAST_SELECTED_FILE` when the screen is scrolled.

Allow `ENABLED`, `DISABLED`, `PIN_EXISTS`, and `BUTTON_EXISTS` to take multiple arguments. Also add:
- Alias `ANY(...)` for `!DISABLED(...)`
- Alias `ANY_PIN(...)` for `PIN_EXISTS(a) || PIN_EXISTS(b) ...`
- Alias `EITHER(A,B)` for `ANY(...)`
- Alias `ALL(...)` and `BOTH(A,B)` for `ENABLED(...)`
- `NONE(...)` for `DISABLED(...)`

* Move special characters to language.h
* Apply some naming standards
* Clean up menu item draw functions
* Rename some Temperature methods
* UI => ExtUI

* Encapsulate common LCD code in a singleton
* Depend more UBL code on UBL_DEVEL_DEBUGGING
  - Since most users don't need the debugging on at all times, this helps reduce the default build size for UBL by over 2K, a little closer to fitting on 128K boards.

* Make lcd_quick_feedback argument optional
* Add click_to_cancel option to wait_for_hotend/bed
* Have G26 use the active nozzle and wait_for_hotend/bed
* Use wait_for_release in UBL G29
* Add 'T' parameter to G26 for an initial tool-change

* Followup to LCD_TIMEOUT_TO_STATUS=0
* Make continuous purge screen fit 20x4
* Unify purge message modes
* Preserve last-set pause header mode