Avoid redundant Lisp_Object <-> struct frame conversions in font API.

Avoid redundant Lisp_Object <-> struct frame conversions in font API.
* font.h (struct font_driver): Change list, match, and list_family
functions to accept struct frame * as first arg.
* font.c (font_score, font_compare, font_sort_entities): Remove
prototypes.
(font_sort_entities, font_list_entities, font_select_entity):
(font_find_for_lface, Flist_fonts, Ffont_family_list): Adjust to
match font API change.
* xfont.c (xfont_list, xfont_match, xfont_list_family):
* ftfont.c (ftfont_list, ftfont_match, ftfont_list_family):
* ftxfont.c (ftxfont_list, ftxfont_match):
* xftfont.c (xftfont_list, xftfont_match):
* nsfont.m (nsfont_list, nsfont_match, nsfont_list_family):
* w32font.c (w32font_list, w32font_match, w32font_list):
(w32font_list_internal, w32_font_match_internal): Likewise.
* xfaces.c (Fx_family_fonts): Adjust user.