- Fix path to `bedlevel.h` include file
- Add default to `case` statements to suppress warnings

Fix #13470

If `openFile` is given `true`, then it has read-only access. Because all the writing occurs on the next line, this breaks SD card as EEPROM.

Fix #13445

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(...)`

Fixes #13410 and redeclaration of `BUTTON_EXISTS`

According to #13397

Reference: #13380

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