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/select.c

@@ -75,17 +75,17 @@ static int our_select(curl_socket_t maxfd,   /* highest socket number */
 
 #ifdef USE_WINSOCK
   /* Winsock select() must not be called with an fd_set that contains zero
-    fd flags, or it will return WSAEINVAL. But, it also cannot be called
-    with no fd_sets at all!  From the documentation:
+     fd flags, or it will return WSAEINVAL. It also cannot be called with
+     no fd_sets at all!  From the documentation:
 
-    Any two of the parameters, readfds, writefds, or exceptfds, can be
-    given as null. At least one must be non-null, and any non-null
-    descriptor set must contain at least one handle to a socket.
+     Any two of the parameters, readfds, writefds, or exceptfds, can be
+     given as null. At least one must be non-null, and any non-null
+     descriptor set must contain at least one handle to a socket.
 
-    It is unclear why Winsock does not handle this for us instead of
-    calling this an error. Luckily, with Winsock, we can _also_ ask how
-    many bits are set on an fd_set. So, let's check it beforehand.
-  */
+     It is unclear why Winsock does not handle this for us instead of
+     calling this an error. Luckily, with Winsock, we can _also_ ask how
+     many bits are set on an fd_set. Therefore, let's check it beforehand.
+   */
   return select((int)maxfd + 1,
                 fds_read && fds_read->fd_count ? fds_read : NULL,
                 fds_write && fds_write->fd_count ? fds_write : NULL,