* 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

Fix #12326

* Fix broken LPC176x build
* Add UBL+HD44780 test for LPC1768

* Apply #pragma once in headers
* Adjust some thermistors formatting
* Misc cleanup and formatting

- Drop `pgm_read_*_near` and let headers choose.
- Define `USE_EXECUTE_COMMANDS_IMMEDIATE` as a conditional.
- Add `process_subcommands_now` for SRAM-based commands.

- Followup fixes for menu refactor
- Fix TMC sanity checks, unused var warnings

- Add `axis_t`, `extruder_t`, `heater_t`, and `fan_t` to eliminate ambiguity, improve type safety.
- Regularized getter/setter argument order and naming.
- `setAxisPosition` no longer stacks moves in the buffer, allowing it to be called repeatedly on each touch ui tap.
- Implement better manual moves for `EXTENSIBLE_UI` (#12205)
- Calling `setAxisPosition_mm` no longer buffers the entire move to the new position, but instead causes small moves towards it to be made during the idle loop. This allows the user to adjust the destination even after the move has started and makes the UI feel much more responsive.
- As suggested by @ejtagle, the new code keeps the planner buffer full to ensure smooth motion without stops and starts.
- Change `En`, `Hn` and `FANn` to zero-based indices.
- Labels consistent with the rest of Marlin code.