Identify database solution for Explorer

[AlejandroCabeza]

We need a database that fully supports all of the Explorer's functional requirements. Ideally, this would be a single database solution to reduce the overhead of maintaining multiple databases.

Current Proposal: SurrealDB

SurrealDB is currently the main candidate due to its potential and promising features. However, as of today (11/12/2024), some capabilities—particularly deserializing graph relationships—do not meet our standards. Further testing and evaluation are required.

StorageBackend was implemented for SurrealDB in this PR, but it was closed (postponed) due to these limitations. The branch will remain protected for potential future use.

Primary Use Cases

1. Fetch a block based on TIP - N
   Retrieve a block by going back N blocks from the current tip.

2. Identify the Nearest Common Ancestor and Plot Paths
   Find the nearest common ancestor of a list of tips and plot the different paths stemming from it.

3. Apply Forking Rules

   • From a given tip, identify the common ancestor and forks from it.
   • Query for chain selection rules.