Preparing for Blox beta, KeyVault V0.2

[alonmuroch]

Checklist:

• Align with EIP2334 (derivation)
• remove wallet support
• testnet/ mainnet derivation paths
• EIP2334/5 export/ import
• Enhanced testing for slashing protection

There is a WIP doc made by prysm where I've added my thoughts on that, we should follow whatever prysm decides to implement to be compatible.
https://docs.google.com/document/d/1u_P8veBtIj97u33y_bhOxmVOJJxkMHGNPoF6TvFhz2w/edit?usp=sharing

for progress: https://github.com/bloxapp/KeyVault/tree/version/v0.2-r.c

[alonmuroch]

@olegshmuelov @lior-blox @roman-blox updated