Have a way to bulk remove properties

[h4x3rotab]

In almost all the cases, the properties should be removed when the NFT is burnt. Now we only have this, but it's less efficient compared with draining an iterator:

rmrk-substrate/pallets/rmrk-core/src/functions.rs

Lines 95 to 106 in f2191fd

 	// Internal function to remove a property for downstream `Origin::root()` calls. 
 	fn do_remove_property( 
 		collection_id: T::CollectionId, 
 		maybe_nft_id: Option<T::ItemId>, 
 		key: KeyLimitOf<T>, 
 	) -> sp_runtime::DispatchResult { 
 		Properties::<T>::remove((&collection_id, maybe_nft_id, &key)); 
  
 		Self::deposit_event(Event::PropertyRemoved { collection_id, maybe_nft_id, key }); 
 		Ok(()) 
 	} 
 }