Eth2.0: Detect block proposals and block auto-updates

[pablomendezroyo]

Context

During an epoch is known who proposes (one validator is randomly selected for each slot to propose a block). If a DAppNode user switches the validator at the time when it was selected as a proposal them it will miss the proposal. This is a remote possibility whereas it is something to avoid.

Approach

When DAppNode user attempts to switch to another ETH client validator, there should be a check to ensure that the validator to be switched will not be a proposer in the next epoch

Deppends on https://github.com/dappnode/DNP_DAPPMANAGER/issues/913

[yangxdGIT]

good project