Consider splitting `zkevm` jsonrpc namespace

[arnaubennassar]

Rationale

Why should this feature exist?

Conceptually, this namespace shares two functionalities:

• Give info specific to the zkevm network that is not covered by the standard Ethereum endpoints. This info is used for the bridge service, for instance. This endpoints should/can be served by any RPC node
• Synchronize the trusted state. This is consumed by non trusted sequencer synchronizers, and although it can be served without problems by any node, it should be only served by the trusted sequencer node and consumed by the other nodes

What are the use-cases?

• Cleaner abstraction
• Separate the logic for the synchronization, so it's more easy to update (for instance, if we decide to move to a pushing rather than polling implementation, a broadcast or P2P mechanismor, ...)

Implementation

Do you have ideas regarding the implementation of this feature?

• Create a new namespace to serve the endpoints needed for the trusted synchronization