[2.0.x] Add thermocouple with AD8495 support

[2.0.x] Sub-menu for ABL with LCD_BED_LEVELING

Co-Authored-By: perkmeister <perkmeister@users.noreply.github.com>

As mentioned in https://github.com/MarlinFirmware/Marlin/issues/9429#issuecomment-385305597



Co-Authored-By: Jack Bradach <jack@bradach.net>

Co-Authored-By: Bob-the-Kuhn <bob-the-kuhn@users.noreply.github.com>

Addressing #10569

From #10531

Co-Authored-By: chriscg9 <chriscg9@users.noreply.github.com>

…and any other platforms where `false`/`true` are defined as `0x0`/`0x1`.

This fixes issue #10550.

Raise an error when an unknown/unsupported G/M command is requires.

This will address #10546

…as with #10540

Co-Authored-By: per1234 <per1234@users.noreply.github.com>