Apply `ENABLED` / `DISABLED` macros to language-related files.

- The contents of EEPROM include filament diameters even with
Volumetric disabled. This change makes `M503` display the full
volumetric settings so that playing back the output of `M503 S0` will
fully restore them.

Just the minimal changes to qr_solve.cpp and .h to get rid of malloc() and free().

Saves about 656 bytes of progmem (library-code)
and 22 bytes for static variables.

Should use exactly the same amount of stack as it did before on the heap.

Discussion at #2541

instead of 1000.  Else we get errors with times over 32 seconds.

and translate them to German.

As suggested in #2521
- Move `ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED` because `SDSUPPORT` is
also required.
- Add a note that endstops must be enabled for the feature to have any
effect

Annoying when trying to figure out if uploading
actually does something.

No need to look for arduino specific avrdude configuration
as distributions ship their own avrdude.conf file that
is compatible with arduino.