Frame remove_all with size limit. (#9106)

* remove prefixed content with limit.

* test match

* factor comment and factor ext limit removal.

* fix benchmark

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

substrate/frame/contracts/src/storage.rs

@@ -33,7 +33,7 @@ use sp_runtime::{
 use sp_core::crypto::UncheckedFrom;
 use frame_support::{
 	dispatch::{DispatchError, DispatchResult},
-	storage::child::{self, KillChildStorageResult, ChildInfo},
+	storage::child::{self, KillStorageResult, ChildInfo},
 	traits::Get,
 	weights::Weight,
 };
@@ -331,14 +331,14 @@ where
 				let removed = queue.swap_remove(0);
 				match outcome {
 					// This should not happen as our budget was large enough to remove all keys.
-					KillChildStorageResult::SomeRemaining(_) => {
+					KillStorageResult::SomeRemaining(_) => {
 						log::error!(
 							target: "runtime::contracts",
 							"After deletion keys are remaining in this child trie: {:?}",
 							removed.trie_id,
 						);
 					},
-					KillChildStorageResult::AllRemoved(_) => (),
+					KillStorageResult::AllRemoved(_) => (),
 				}
 			}
 			remaining_key_budget = remaining_key_budget