M32 R1/ M32 R to reprint last file

[ampex_fhm]

DWC already has this via the 'print another' button, however it is only possible because DWC keeps track of the last printed file on its own.

This way, one can use a macro or (maybe down the road) a button in PanelDue to accomplish the same thing.

M32 R1
or
M32 R

reprints the last file. Only works if a file has been printed since poweron and throws an error otherwise. Or maybe put it in a separate Gcode altogether since the spec of M32 does not take parameters apparently (to avoid collisions with files that are named "R1" or "R").