SCORU/Node: use indexed file for storage

Context

Replaces the Irmin store for the smart rollup node by a store based on indexed files (excepted for the DAL data for now).

This is the (almost) final MR for the refactoring of the smart rollup node store.

Fixes #4392 (closed), #3471 (closed).

Depends on:

• !7101 (merged)
• !7122 (merged)
• !7132 (merged)
• !7135 (merged)
• !7170 (merged)
• !7171 (merged)
• !6875 (merged)

Dependency graph of staked MRs for this feature is as such:

graph BT
    !7251 --> !7170
    !7251 --> !6875 
    !7170 --> !7135
    !7135 --> !7132
    !7132 --> !7122
    !7122 --> !7101
    !7251 --> !7171
    !7292 --> !7251
    !7298 --> !7170

    style !7171 fill:#afa
    style !7101 fill:#afa
    style !7122 fill:#afa
    style !7132 fill:#afa
    style !7135 fill:#afa
    style !7170 fill:#afa
    style !7298 fill:#afa
    style !6875 fill:#afa
    style !7251 fill:#afa
    style !7292 fill:#afa

Example in storage reduction

Test run on a rollup with light traffic for 1000 blocks.

Indexed store

40K	storage/levels_to_hashes
112K	storage/messages
8,0K	storage/commitments
432K	storage/inboxes
344K	storage/l2_blocks
8,0K	storage/commitments_published_at_level
16K	storage/irmin_store
968K	storage
1,3M	context
2,2M	total

Before this MR

7,3M	storage
1,3M	context
8,5M	total

➡️ 87% reduction in store

➡️ 74% reduction overall

Before all storage refactoring MRs

264M	storage
1,3M	context
265M	total

➡️ 99.63% reduction in store

➡️ 99.17% reduction overall

Manually testing the MR

Run a rollup node and check the storage size on disk.