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/url.h

@@ -85,7 +85,7 @@ CURLcode Curl_conn_upkeep(struct Curl_easy *data,
 
 /**
  * Always eval all arguments, return the first
- * result != (CURLE_OK|CURLE_AGAIN) or `r1`.
+ * result != (CURLE_OK | CURLE_AGAIN) or `r1`.
  */
 CURLcode Curl_1st_fatal(CURLcode r1, CURLcode r2);