tidy-up: miscellaneous

- vms/curlmsg_vms.h: delete unused/commented code.
- vtls/schannel_verify: sort includes.
- typecheck-gcc.h: fix indent and alignment.
- lib/config-win32.h: drop idle `#undef`.
- spacecheck: check for stray empty lines before after curly braces.
- make literals more readable: 1048576 -> 1024 * 1024
- scope variables.
- use ISO date in a comment.
- drop redundant parentheses.
- drop empty comments.
- unfold lines.
- duplicate/stray spaces in comments.
- fix indent, whitespace, minor typos.

Closes #20690

src/tool_vms.c

@@ -97,7 +97,7 @@ void vms_special_exit(int code, int vms_show)
 #endif
 
   if(code > CURL_LAST) {   /* If CURL_LAST exceeded then */
-    vms_code = CURL_LAST;  /* curlmsg.h is out of sync.  */
+    vms_code = CURL_LAST;  /* curlmsg.h is out of sync. */
   }
   else {
     vms_code = vms_cond[code] | vms_show;