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

scripts/badwords

@@ -219,9 +219,8 @@ if(@exact) {
 }
 
 # Build a single combined regex for removing whitelisted content
-my $re_wl;
 my $pat = join('|', map { $_ } @whitelist);
-$re_wl = qr/($pat)/;
+my $re_wl = qr/($pat)/;
 
 my $errors = 0;