clutter: Use fribidi directly to determine text direction

The API helpers from pango are marked as deprecated, so lets stop using them. The functions in clutter-text.c are more or less a direct copy of the ones in pango, while the one in clutter-keymap-x11.c are more open coded variant of one of the functions in pango.

Copyright from the corresponding files are added to the files the copied functions are added to.