Move the glyph to character(s) mapping to CommonSalLayout where we have
enough information to do this properly. This correctly handles ligatures
at end of run that wasn’t handled before, and also fixes a bug in the
PDF writer code when there is more than one ligature in the run (it
forgot to clear aCodeUnitsPerGlyph vector after each iteration). Also
drop the “temporary” fix for rotated glyph from 2009 that does not seem
to be needed now (the document from that bug exports correctly after this
change).

Change-Id: I5b5b1f4470bbd0ef05cbbc86dfa29d2ff51249ea
Reviewed-on: https://gerrit.libreoffice.org/51617Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>