* 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.
- 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.
* Fix to isPrintingFromMedia()
- isPrintingFromMedia() will now return true even if SD print is paused.
- isPrintingFromMediaPaused() allows UI to determine if the print is paused.
* Don't use _delay_us in minkill (#12145)
- In HAL_DUE, _delay_us is simply an alias for delay, which causes the board to hang and subsequently reboot due to the watchdog timer.
* Shorten code with IFSD macro
- Add methods to access print counter data
- Clean up some inconsistent method names
- Clear lcd status after filament change
- Implement `lcd_reset_status` so it works like UltraLCD
* Clean up Temperature PID
* Improve EEPROM read/write/validate
* Group `SINGLENOZZLE` saved settings
* Group planner saved settings
* Group filament change saved settings
* Group skew saved settings
* Group `FWRETRACT` saved settings
