racket/draw: change font face name interpretation again

Treat a "face" as a font description only if it has a comma,
otherwise go back to treating it as a family name.

This change fixes the problem of parsing "Times New Roman"
as "Times New, Roman".

original commit: 530b35379830819f7de46c80dc9f9691a17fcc7b

collects/tests/gracket/dc.rktl

@@ -502,4 +502,9 @@
 
 ;; ----------------------------------------
 
+(test #f 'no-commas (ormap (lambda (s) (regexp-match? #rx"," s)) (get-face-list)))
+(test #t 'all-commas (andmap (lambda (s) (regexp-match? #rx"," s)) (get-face-list #:all-variants? #t)))
+
+;; ----------------------------------------
+
 (report-errs)