state-machine: Move all functionality from trie backend to the essence (#10904)

* state-machine: Move all functionality from trie backend to the essence

This is required for some future changes of me and it also makes more sense to have all the
functionality inside the essence. Besides that it changes the child root cache to directly
cache the hash.

* Update primitives/state-machine/src/trie_backend_essence.rs

Co-authored-by: cheme <[email protected]>

* FMT

Co-authored-by: cheme <[email protected]>