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

lib/idn.c

@@ -33,10 +33,10 @@
 #include <idn2.h>
 
 #if defined(_WIN32) && defined(UNICODE)
-#define IDN2_LOOKUP(name, host, flags)                                  \
+#define IDN2_LOOKUP(name, host, flags)                           \
   idn2_lookup_u8((const uint8_t *)name, (uint8_t **)host, flags)
 #else
-#define IDN2_LOOKUP(name, host, flags)                          \
+#define IDN2_LOOKUP(name, host, flags)                         \
   idn2_lookup_ul((const char *)(name), (char **)(host), flags)
 #endif
 #endif /* USE_LIBIDN2 */