CHANGED: The text variable ${SHEETNAME} now always represents the name of the
sheet when used anywhere in the schematic editor, including the title block
ADDED: A new text variable ${SHEETPATH} which is replaced with the path to the
current sheet - e.g. "/Sheet 1/Sheet 2".
To ensure backward compatibility, the default drawing sheet now uses
${SHEETPATH}. Custom drawing sheets will need to be manually edited.
Also cleans up the dialog a bit.
Also changes the workings of NormalizePath to return the input if
it couldn't be shortened which saves open coding that behaviour in
all its callers.
Fixes https://gitlab.com/kicad/code/kicad/issues/9036
Found via `codespell -q 3 -S *.po,./thirdparty -L aactual,acount,aline,alocation,alog,anormal,anumber,aother,apoints,aparent,aray,dout,einstance,modul,ot,overide,serie,te,,tesselate,tesselator,tht`
Keeping them in base_units means that we can't introduce
any dependence on these functions to anything that needs to
compile without one of the unit defines (EESCHEMA, PCBNEW, etc)