Fix #14045

Low or unknown probe clearance on init (even at powerup) is a risk and therefore, a deploy should be avoided because dragging the pin is possible: A deploy goes into alarm if it can't extend fully and then the subsequent stow will fail.

- Add local UI methods to get heater timeout state.
- Add methods to resume timed-out heaters.
- Re-enable heaters on UI temperature request.
- Make `ExtUI` show a dialog box if pause needs a button press after reheat.

`check_version` in state -5 should not be needed since it has already been called in state -4 and the tested build nr is only updated in state -4.

…And save backlash, fil. sensor, ExtUI userdata to EEPROM.

- Save and restore workspace offsets
- Add retract and purge (hidden) options
- Always restore axis relative modes
- Use added `G92.9` to do position restores