Own acceptance not stored in DKG DB

[CluEleSsUK]

After the leader has made a proposal, nodes that existed in the network at the previous epoch are permitted to accept or reject a proposal. These acceptances and rejections are gossiped amongst the group. Currently, a node's own acceptance/rejection is not stored in the DKG correctly. While not a problem per se, it's an inconsistency and ideally every node would end up with the same DKG state during a DKG (key share notwithstanding) so we can implement fancier workflows (like rolling back if parties end up with a different state).