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

docs/examples/websocket.c

@@ -73,7 +73,7 @@ retry:
   result = curl_ws_recv(curl, buffer, sizeof(buffer), &rlen, &meta);
   if(result == CURLE_OK) {
     /* on small PING content, this example assumes the complete
-     * PONG content arrives in one go. Larger frames will arrive
+     * PONG content arrives in one go. Larger frames arrive
      * in chunks, however. */
     if(meta->flags & CURLWS_PONG) {
       int same = 0;