tidy-up: miscellaneous

- examples: sync debug output printf masks.
- INSTALL-CMAKE.md: tidy up section for some options.
- curl_sha512_256: delete comment suggesting an optimization.
- vtls/keylog: scope a variable.
- vtls/openssl: make a source code URL a permalink.
- vtls/schannel: drop redundant parentheses.
- test1119.pl: robustify `$1` -> `$s`.
- sync arg names in comments to match the code.
- tidy up and minor fixes to comments.
- fix formatting/indenting/comment/newline/include nits.
- move `UNITTEST` protos next to definitions, sync their argument names.
- make variables static.
- add parentheses to Perl `open()` calls.
- drop unnecessary double quotes in Perl.
- clang-format.

Closes #21000

src/tool_libinfo.c

@@ -132,7 +132,6 @@ size_t feature_count;
  * the latter is not returned by curl_version_info(), it is built from
  * the returned features bit mask.
  */
-
 CURLcode get_libcurl_info(void)
 {
   CURLcode result = CURLE_OK;
@@ -197,7 +196,6 @@ CURLcode get_libcurl_info(void)
  * a given protocol and thus allows comparing pointers rather than strings.
  * In addition, the returned pointer is not deallocated until the program ends.
  */
-
 const char *proto_token(const char *proto)
 {
   const char * const *builtin;