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/bufq.h

@@ -132,8 +132,8 @@ void Curl_bufq_initp(struct bufq *q, struct bufc_pool *pool,
                      size_t max_chunks, int opts);
 
 /**
- * Reset the buffer queue to be empty. Will keep any allocated buffer
- * chunks around.
+ * Reset the buffer queue to be empty. Keep any allocated buffer chunks
+ * around.
  */
 void Curl_bufq_reset(struct bufq *q);
 
@@ -243,7 +243,7 @@ CURLcode Curl_bufq_sipn(struct bufq *q, size_t max_len,
 
 /**
  * Write buf to the end of the buffer queue.
- * Will write bufq content or passed `buf` directly using the `writer`
+ * Write bufq content or passed `buf` directly using the `writer`
  * callback when it sees fit. 'buf' might get passed directly
  * on or is placed into the buffer, depending on `len` and current
  * amount buffered, chunk size, etc.