L2Node: Add a tree command to durable storage shell explorer

What

Add a tree command in the durable storage shell explorer

Why

It's useful to explorer all the sub-tree of a specific key.

How

• Add the new tree command with two parameters : path and optional depth (by default 10)

Manually testing the MR

octez-evm-node shell --data-dir ~/tezos_storage/test_local_observer --block finalized
> tree /evm --depth 2
|-- admin
|-- current_block_header
|-- l1_level
|-- maximum_gas_per_transaction
|-- storage_version
|-- sequencer_pool_address
|-- delayed_inbox_min_levels
|-- kernel_version
|-- info_per_level
|   `-- timestamp
|-- sequencer
|-- evm_version
|-- delayed_bridge
|-- world_state
|   |-- indexes
|   |   `-- blocks
|   |-- eth_codes
|   |   |-- 133ed58261c592a910d618f8dbcfb43bdc2875d7838b90306f686547e09cfa92