Ticket #13228

If `INCH_MODE_SUPPORT` is undefined, G20 is an unknown command as it should be (Marlin is, by default, operating in metric mode). G21, however, is found in many slicers and printer start gcode sections and should be accepted (as a NOOP) to avoid the unknown commands.

Fix #12643
Only factors above 1 can have a 'positive' effect.

Co-Authored-By: shitcreek <45380455+shitcreek@users.noreply.github.com>

Fix #9799 — hopefully not a unicorn

Fix #13184

See #8010

See #13000

See #13065

Observing from the console, it makes the most sense to do `//action:probe_retry` before executing commands.

- Turn off bed leveling prior to calibrating.
    - This prevents lateral probes from having a Z component that
      triggers the Z endstop and causes the motion to be aborted.
- Got rid of static const float arrays "dimension" and "true_center"
    - Frees up 24 bytes of SRAM
- Changed incorrect use of "bool" for float in backlash macros.
    - Replaced arguments with 0.0f and 1.0f for clarity.
- Now only disables soft endstops (since calibration cube is outside of bed)
    - Not necessary to disable global endstops

* Remove untested displays add TMC2130 configs.
* Remove references to the ReARM, delete untested displays. Add TMC2130 settings. Cleanup spacing, etc.

- Fix compile error when accessing `process_subcommands_now_P`.
- Use `const` var eliminating double-negative (to make code more understandable).