tidy-up: miscellaneous

- apply more clang-format.
- lib/version: use `CURL_ARRAYSIZE()`.
- INSTALL-CMAKE.md: sync-up an option description with others.
- examples: delete unused main args.
- examples/ftpgetinfo: document `_CRT_SECURE_NO_WARNINGS` symbol.
- delete remaining stray duplicate lines.
- acinclude.m4: drop an unnecessary x-hack.
- vtls/mbedtls: join a URL split into two lines.
- src/tool_cb_see: add parentheses around macro expressions.
- src/tool_operate: move literals to the right side of comparisons.
- libtests: sync up fopen/fstat error messages between tests.
- curl_setup.h: replace `if ! defined __LP64` with `ifndef __LP64`.
  I assume it makes no difference on Tandem systems, as the latter form
  is already used in `include/curl/system.h`.

Closes #20018

src/tool_formparse.c

@@ -840,9 +840,9 @@ int formparse(const char *input,
         part->headers = headers;
         headers = NULL;
         if(res == CURLE_READ_ERROR) {
-            /* An error occurred while reading stdin: if read has started,
-               issue the error now. Else, delay it until processed by
-               libcurl. */
+          /* An error occurred while reading stdin: if read has started,
+             issue the error now. Else, delay it until processed by
+             libcurl. */
           if(part->size > 0) {
             warnf("error while reading standard input");
             goto fail;