Dynamic Benchmarking DB Whitelist (#6815)

* Add `get_whitelist` api

* add whitelisted caller

* Whitelist caller

* remove caller 0

* initial piping of origin (not actual value yet)

* remove attempt to pass origin around

* Add whitelist for `DidUpdate` storage on `pallet_timestamp`

* fix traits

* only add to whitelist if !contains

* PassBy not implemented error

* Whitelist read/writes explicitly per key

* update docs

* reduce trait constraint

* copy pasta

* Apply suggestions from code review

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

* rename functions @apopiak

* missed some renaming

* enable doc tests

* Update docs

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

substrate/primitives/state-machine/src/ext.rs

@@ -26,7 +26,7 @@ use crate::{
 use hash_db::Hasher;
 use sp_core::{
 	offchain::storage::OffchainOverlayedChanges,
-	storage::{well_known_keys::is_child_storage_key, ChildInfo},
+	storage::{well_known_keys::is_child_storage_key, ChildInfo, TrackedStorageKey},
 	traits::Externalities, hexdisplay::HexDisplay,
 };
 use sp_trie::{trie_types::Layout, empty_child_trie_root};
@@ -609,7 +609,11 @@ where
 		self.backend.reset_read_write_count()
 	}
 
-	fn set_whitelist(&mut self, new: Vec<Vec<u8>>) {
+	fn get_whitelist(&self) -> Vec<TrackedStorageKey> {
+		self.backend.get_whitelist()
+	}
+
+	fn set_whitelist(&mut self, new: Vec<TrackedStorageKey>) {
 		self.backend.set_whitelist(new)
 	}
 }