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/cf-socket.c

@@ -688,8 +688,8 @@ static CURLcode bindlocal(struct Curl_easy *data, struct connectdata *conn,
           if(scope_ptr) {
             /* The "myhost" string either comes from Curl_if2ip or from
                Curl_printable_address. The latter returns only numeric scope
-               IDs and the former returns none at all. So the scope ID, if
-               present, is known to be numeric */
+               IDs and the former returns none at all. Making the scope ID,
+               if present, known to be numeric */
             curl_off_t scope_id;
             if(curlx_str_number((const char **)CURL_UNCONST(&scope_ptr),
                                 &scope_id, UINT_MAX))