Issue 4914/2: convert-ly rule for removing Output_property_engraver

Issue 4914/2: convert-ly rule for removing Output_property_engraver

It's highly unlikely that users will redefine the Score context from
scratch, so the convert-ly rule just removes every occurence of
Output_property_engraver from user source.  Obviously, when running the
rule on the LilyPond code base, we will need to fix up the Score
engraver manually to retain the Output_property_engraver .