tidy-up: miscellaneous

- INSTALL-CMAKE.md: add missing periods, text fixes.
- md4, md5: sync variables names.
- curl_trc: sync an argument type.
- docs/examples: sync debug/trace function copies, constify, tidy-ups.
- replace commented code with `#if 0`.
- drop redundant parenthesis (macro values, `return`, around single
  variables, function calls).
- fix indentation, apply clang-format in places.

Closes #20481

lib/conncache.c

@@ -52,7 +52,7 @@
     }                                                                   \
   } while(0)
 
-#define CPOOL_UNLOCK(c,d)                                               \
+#define CPOOL_UNLOCK(c, d)                                              \
   do {                                                                  \
     if(c) {                                                             \
       DEBUGASSERT((c)->locked);                                         \