Companion for paritytech/substrate#12795 (#6374)

* Begin removing `parity-util-mem`; remove `collect_memory_stats`

* Update some dependencies that were using `parity-util-mem`

* Remove `trie-memory-tracker` feature

* Update Cargo.lock

* Update `kvdb-shared-tests`

* Add back jemalloc

* Add missing license header

* update lockfile for {"substrate"}

Co-authored-by: parity-processbot <>
Co-authored-by: Andronik <write@reusable.software>