build: tidy-up MSVC CRT warning suppression macros

- curl_setup.h: replace `_CRT_SECURE_NO_DEPRECATE` with
  `_CRT_SECURE_NO_WARNINGS`, which seems to be the preferred,
  more recent macro for this. Also syncing with libssh2.
  They are equivalent for curl sources with the supported compilers.
- cmake: stop setting `_CRT_SECURE_NO_DEPRECATE` globally for examples.
- examples: suppress CRT deprecation warnings on a per-file basis.
  To make it work when compiling examples out of curl's build systems.
  Use `_CRT_SECURE_NO_WARNINGS`.
- examples: document the functions requiring `_CRT_SECURE_NO_WARNINGS`.
- examples/block_ip: delete superfluous `_CRT_SECURE_NO_WARNINGS`.
- examples/block_ip: limit `_CRT_NONSTDC_NO_DEPRECATE` to MSVC.
- examples/log_failed_transfers: fix to set `_CRT_SECURE_NO_WARNINGS`
  before headers and limit to MSVC.
- curl_setup.h: document which SDKs support `_CRT_NONSTDC_NO_DEPRECATE`.

Closes #19175

docs/examples/ftpupload.c

@@ -21,14 +21,26 @@
  * SPDX-License-Identifier: curl
  *
  ***************************************************************************/
+/* <DESC>
+ * Performs an FTP upload and renames the file just after a successful
+ * transfer.
+ * </DESC>
+ */
+#ifdef _MSC_VER
+#ifndef _CRT_SECURE_NO_WARNINGS
+#define _CRT_SECURE_NO_WARNINGS  /* for fopen(), strerror() */
+#endif
+#endif
+
 #include <stdio.h>
 #include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 
 #include <curl/curl.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <errno.h>
+
 #ifdef _WIN32
 #include <io.h>
 #undef stat
@@ -40,12 +52,6 @@
 #include <unistd.h>
 #endif
 
-/* <DESC>
- * Performs an FTP upload and renames the file just after a successful
- * transfer.
- * </DESC>
- */
-
 #define LOCAL_FILE      "/tmp/uploadthis.txt"
 #define UPLOAD_FILE_AS  "while-uploading.txt"
 #define REMOTE_URL      "ftp://example.com/"  UPLOAD_FILE_AS