ExEx Oracle Full Example

[loocapro]

A simple (optional: stake weighted) oracle protocol operates in the following phases:

1. Observe data from off-chain source
2. Attest to that data by signing on it
3. Broadcast the signed payload to its peers -- this can happen either on a fixed interval basis, or triggered as a response to an external action e.g. an onchian event being emitted as a result of the "request / callback" pattern, frequently seen in ChainLink or Axiom-style contracts
4. Track signatures
5. Once it hits quorum of signatures, send it out either directly to the place where the data will trigger an action (i.e. it handles also being a "keeper", e.g. submitting the signed oracle 2-of-3 multisig data to a smart contract's callback function, or even archiving it to blobs) or it proceeds to expose it over an (optionally authenticated) API to a user querying it, for self-relaying.

Originally posted by @gakonst in #18 (comment)

### Tasks
- [ ] https://github.com/paradigmxyz/reth-exex-examples/issues/19
- [ ] https://github.com/paradigmxyz/reth-exex-examples/issues/24