Switch to new kvdb-rocksdb (#4186)

* Switch to new rocksdb with some hacks to resolve linking errors

Rocksdb and `wasmtime-environ` both link `zstd`. In the final link step,
this leads to linking errors because of duplicate symbols. The linked
Rocksdb fixes this by using `zstd-sys` as well. However, this currently
also requires modifications in `zstd-sys`. Someone will need to come up
with a better implementation.

* Switch to new version of kvdb-rocksdb

* Update client/db/src/utils.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

substrate/client/db/src/offchain.rs

@@ -43,7 +43,7 @@ impl LocalStorage {
 	/// Create new offchain storage for tests (backed by memorydb)
 	#[cfg(any(test, feature = "test-helpers"))]
 	pub fn new_test() -> Self {
-		let db = Arc::new(::kvdb_memorydb::create(crate::utils::NUM_COLUMNS));
+		let db = Arc::new(kvdb_memorydb::create(crate::utils::NUM_COLUMNS));
 		Self::new(db as _)
 	}