UI: show an error when a search fails

Useful in cases when making a typo before pressing enter.

source/blender/editors/interface/interface_handlers.c

@@ -3357,6 +3357,9 @@ static void ui_textedit_end(bContext *C, uiBut *but, uiHandleButtonData *data)
 
           /* ensure menu (popup) too is closed! */
           data->escapecancel = true;
+
+          WM_reportf(RPT_ERROR, "Failed to find '%s'", but->editstr);
+          WM_report_banner_show();
         }
       }