chore: finalized sync e2e test

[twoeths]

Motivation

Scan electra codes through e2e tests

Description

Some issues detected through this test:

• submitPoolAttestations: api deserialization
• publishAggregateAndProofs: api deserialization + invalid signatures
• initializeBeaconStateFromEth1: miss setting balances array in deposits

The test passed with some TODOs + hard code. This is a preparation for the interop, need to work on separate PRs from this before including the test in the end