During thermal errors all fans are set to full speed.
When the print is resumed or stopped *and* the thermal error is gone,
also restore the autofan state.
Fixes#3893
Having the original PRINTER_ACTIVE macro copied at multiple spots doesn't make sense.
Refactoring it into a non-inline function saved ~400 bytes of code.
It should be safe in terms of performance, all occurrences are at non-time critical spots.
