Read through the specs and started building upon PoC.

**Updates**
* Started building upon the [epbs](https://github.com/prysmaticlabs/prysm/tree/epbs) branch in the Prysm client
* Created a draft [PR#13046](https://github.com/prysmaticlabs/prysm/pull/13046) based on the ethereum [consensus specs](https://github.com/ethereum/consensus-specs)
* Faced some issues compiling the gRPC files due to incompatibility of Bazel with MacOS

**Next Steps**
Improve upon the PR based on the review, see alternatives to compile the gRPC if not through already present scripts that uses Bazel.