util: Don't interpret quotes by default in extract_first_word

This adds an EXTRACT_QUOTES option to allow the previous behaviour, of
not interpreting any character inside ' or " quotes as separators.

src/shared/condition.c

@@ -101,7 +101,7 @@ static int condition_test_kernel_command_line(Condition *c) {
                 _cleanup_free_ char *word = NULL;
                 bool found;
 
-                r = extract_first_word(&p, &word, NULL, EXTRACT_RELAX);
+                r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX);
                 if (r < 0)
                         return r;
                 if (r == 0)