Enhancements to G425 (#13159)

- 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