tidy-up: docs, comments, typos, whitespace

- GHA/windows: mention `IgnoreStandardErrorWarningFormat=true`
  in comment.
- cmake: fix MIT/GNU GSS order in messages.
- drop some exclamation marks from messages.
- drop redundant ending newlines from messages.
- fold/unfold where possible.
- fix indent, whitespace, typos and other nits.

Closes #22185

lib/formdata.c

@@ -186,7 +186,7 @@ static void free_formlist(struct FormInfo *ptr)
  * curl_formadd(&post, &last, CURLFORM_COPYNAME, "name",
  *              CURLFORM_PTRCONTENTS, ptr, CURLFORM_CONTENTSLENGTH, 10L,
  *              CURLFORM_END);
- * (if CURLFORM_CONTENTSLENGTH is missing strlen () is used)
+ * (if CURLFORM_CONTENTSLENGTH is missing strlen() is used)
  *
  * storing a filename (CONTENTTYPE is optional!):
  * curl_formadd(&post, &last, CURLFORM_COPYNAME, "name",