examples: re-enable console examples for C2, C6, H2

- Split the sleep-related system commands into a separate file
- Don't compile that file and don't register sleep commands for H2 yet
- Exclude Wi-Fi commands if the chip doesn't have Wi-Fi

examples/system/console/advanced/main/console_example_main.c

@@ -19,6 +19,7 @@
 #include "esp_vfs_fat.h"
 #include "nvs.h"
 #include "nvs_flash.h"
+#include "soc/soc_caps.h"
 #include "cmd_system.h"
 #include "cmd_wifi.h"
 #include "cmd_nvs.h"
@@ -154,8 +155,11 @@ void app_main(void)
 
     /* Register commands */
     esp_console_register_help_command();
-    register_system();
+    register_system_common();
+    register_system_sleep();
+#if SOC_WIFI_SUPPORTED
     register_wifi();
+#endif
     register_nvs();
 
     /* Prompt to be printed before each line.