Add ExtUI::onStatusChanged_P (#17543)

Marlin/src/feature/pause.cpp

         host_prompt_do(PROMPT_INFO, GET_TEXT(MSG_REHEATING));
       #endif
       #if ENABLED(EXTENSIBLE_UI)
-        ExtUI::onStatusChanged(GET_TEXT(MSG_REHEATING));
+        ExtUI::onStatusChanged_P(GET_TEXT(MSG_REHEATING));
       #endif
 
       // Re-enable the heaters if they timed out

Marlin/src/lcd/extui/ui_api.cpp

     onUserConfirmRequired(msg);
   }
 
+  void onStatusChanged_P(PGM_P const pstr) {
+    char msg[strlen_P(pstr) + 1];
+    strcpy_P(msg, pstr);
+    onStatusChanged(msg);
+  }
+
   FileList::FileList() { refresh(); }
 
   void FileList::refresh() { num_files = 0xFFFF; }

Marlin/src/lcd/extui/ui_api.h

   void onUserConfirmRequired(const char * const msg);
   void onUserConfirmRequired_P(PGM_P const pstr);
   void onStatusChanged(const char * const msg);
+  void onStatusChanged_P(PGM_P const pstr);
   void onFactoryReset();
   void onStoreSettings(char *);
   void onLoadSettings(const char *);