Rework storage iterators (#13284)

* Rework storage iterators

* Make sure storage iteration is also accounted for when benchmarking

* Use `trie-db` from crates.io

* Appease clippy

* Bump `trie-bench` to 0.35.0

* Fix tests' compilation

* Update comment to clarify how `IterArgs::start_at` works

* Add extra tests

* Fix iterators on `Client` so that they behave as before

* Add extra `unwrap`s in tests

* More clippy fixes

* Come on clippy, give me a break already

* Rename `allow_missing` to `stop_on_incomplete_database`

* Add `#[inline]` to `with_recorder_and_cache`

* Use `with_recorder_and_cache` in `with_trie_db`; add doc comment

* Simplify code: use `with_trie_db` in `next_storage_key_from_root`

* Remove `expect`s in the benchmarking CLI

* Add extra doc comments

* Move `RawIter` before `TrieBackendEssence` (no code changes; just cut-paste)

* Remove a TODO in tests

* Update comment for `StorageIterator::was_complete`

* Update `trie-db` to 0.25.1

substrate/primitives/trie/src/cache/mod.rs

@@ -438,8 +438,8 @@ enum ValueCache<'a, H: Hasher> {
 
 impl<H: Hasher> ValueCache<'_, H> {
 	/// Get the value for the given `key`.
-	fn get<'a>(
-		&'a mut self,
+	fn get(
+		&mut self,
 		key: &[u8],
 		shared_cache: &SharedTrieCache<H>,
 		stats: &HitStats,