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

src/tool_cb_see.c

@@ -78,7 +78,7 @@ int tool_seek_cb(void *userdata, curl_off_t offset, int whence)
 
   if(curl_lseek(per->infd, offset, whence) == LSEEK_ERROR)
     /* could not rewind, the reason is in errno but errno is not portable
-       enough and we do not actually care that much why we failed. We will let
+       enough and we do not actually care that much why we failed. We let
        libcurl know that it may try other means if it wants to. */
     return CURL_SEEKFUNC_CANTSEEK;