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

m4/curl-functions.m4

@@ -418,7 +418,7 @@ struct SocketIFace *ISocket = NULL;
 #  else
 struct Library *SocketBase = NULL;
 #  endif
-#  define select(a,b,c,d,e) WaitSelect(a,b,c,d,e,0)
+#  define select(a, b, c, d, e)  WaitSelect(a, b, c, d, e, 0)
 #endif
 /* includes end */"
   AC_CHECK_HEADERS(