Feature/partial tree

[EvgenKor]

Added support for partial tree sync by a client (with specified index), rollbacking, wiping and client self-healing:

• Building tree siblings to get relayer ability calculate necessary tree nodes to support client's partial tree (getLeftSiblings method in libzkbob_rs::merkle)
• Calculating Merkle tree root for the specified index without any tree modifications (get_root_at method in libzkbob_rs::merkle)
• Supporting tree built from the specified index (store first_index, sync state with siblings) (add_leafs_commitments_and_siblings method in libzkbob_rs::merkle)
• Tree rollback function was optimized. Currently it works much more faster (rollback method in libzkbob_rs::merkle)
• Rollback currently supports tx sparse array and state (not only Merkle tree) (rollback method in libzkbob_rs::client::state)
• Added stable index value to the Merkle tree database to support client smooth rollback for self-healing
• Wipe methods for state and Merkle tree
• Updated library libzkbob-rs-node to support siblings, stable indexes and wipe methods
• Updated library libzkbob-rs-wasm to support all integrated methods on the client library side
• Integrated needed unit tests for new and updated methods

This branch can be tested along zkbob-client-js library and zkbob-console tool with associated branches

[AllFi]

It works fine in zkbob-console. The changes look good to me.

[AllFi]

Yes, kvdb-web implementation of DeletePrefix doesn't look correct.