badwords: rework exceptions, fix many of them

Also:
- support per-directory and per-upper-directory whitelist entries.
- convert badlist input grep tweak into the above format.
  (except for 'And' which had just a few hits.)
- fix many code exceptions, but do not enforce.
  (there also remain about 350 'will' uses in lib)
- fix badwords in example code, drop exceptions.
- badwords-all: convert to Perl.
  To make it usable from CMake.
- FAQ: reword to not use 'will'. Drop exception.

Closes #20886

lib/dynhds.h

@@ -167,7 +167,7 @@ CURLcode Curl_dynhds_h1_add_line(struct dynhds *dynhds,
 
 /**
  * Add the headers to the given `dynbuf` in HTTP/1.1 format with
- * cr+lf line endings. Will NOT output a last empty line.
+ * CR+LF line endings. Does NOT output a last empty line.
  */
 CURLcode Curl_dynhds_h1_dprint(struct dynhds *dynhds, struct dynbuf *dbuf);