Validator Network does not always correctly resolve a validator id to the correct Peer

[nibhar]

The Validator network needs to know the validator ids for a given epoch before the next voting takes place, namely either a macro block or a view change. Currently that is part of a task spawned in the beginning of an epoch, but that is not necessarily executed fast enough to make the mapping available. We must make sure that whenever a voting process starts the validator id to peer mapping is accurate and up to date.