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/http_chunks.c

@@ -258,12 +258,12 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
             size_t trlen = curlx_dyn_len(&ch->trailer);
             if(cw_next)
               result = Curl_cwriter_write(data, cw_next,
-                                          CLIENTWRITE_HEADER|
+                                          CLIENTWRITE_HEADER |
                                           CLIENTWRITE_TRAILER,
                                           tr, trlen);
             else
               result = Curl_client_write(data,
-                                         CLIENTWRITE_HEADER|
+                                         CLIENTWRITE_HEADER |
                                          CLIENTWRITE_TRAILER,
                                          tr, trlen);
             if(result) {