- 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

- Only save to PLR file on moves with E and X or Y
- Save to PLR after any long-ish Z downward move

Allow `ENABLED`, `DISABLED`, `PIN_EXISTS`, and `BUTTON_EXISTS` to take multiple arguments. Also add:
- Alias `ANY(...)` for `!DISABLED(...)`
- Alias `ANY_PIN(...)` for `PIN_EXISTS(a) || PIN_EXISTS(b) ...`
- Alias `EITHER(A,B)` for `ANY(...)`
- Alias `ALL(...)` and `BOTH(A,B)` for `ENABLED(...)`
- `NONE(...)` for `DISABLED(...)`

See https://github.com/pinchies/Marlin/pull/1#issuecomment-471388743