feat: side-load additional contracts for indexing

[seanmcgary]

Summary

Currently the Sidecar is responsible for indexing only the core contracts that make up the EigenLayer protocol. We've heard from other potential customers (AVSs, operators, LRTs, custodians, etc) that their existing use-cases require data from additional contracts.

The goal of this feature is to give customers the option of being able to index the logs and events from any other contracts they desire, without polluting the default state of the Sidecar which will remain focused on the EigenLayer protocol.

Requirements

Add a cli to sidecar called load-contracts that will take a JSON blob and load contracts into the database to be used for indexing

TODO

• [] Defined the JSON blob spec

[james-eigen]

@seanmcgary what are example use cases customers might have for sideloading external contracts?

[seanmcgary]

@james-eigen great question. Some possible use-cases that have come up:

• LRTs and/or AVSs wanting to use the sidecar for rewards data but need to also join in their own on-chain state. Typically these folks are running their own kind of indexers currently, so allowing them to specify additional contracts reduces their operational complexity.
• Our own data team currently runs an indexer that we built in-house that is very similar to the sidecar. Currently they index other contracts that are also valuable to operational metrics that are adjacent to the EigenLayer protocol, but not directly the protocol. For example, indexing events from the EIGEN token contract is one big one. Like the first point, if we can enable side-loaded contract indexing, this reduces our own internal operational overhead.