Replace 5 arguments with a single struct as the same arguments are used in many places. This didn't read well and was confusing with both arguments named `val` & `value` in the case of WM_modalkeymap_add_item.
Replace 5 arguments with a single struct as the same arguments are used in many places. This didn't read well and was confusing with both arguments named `val` & `value` in the case of WM_modalkeymap_add_item.