Display in the UI when I have voted on a particular proposal (before the proposal has ended)

[ianconsolata]

Right now, when you cast a vote there is no feedback in the UI showing that you have already voted for a particular proposal.

While we want to hide the contents of the vote, we should still display something in the UI that indicates a particular vote was cast.

We could record this information privately in the database, or we could pull a proposal ID out of the time lock encryption blob and put it into the on chain message.

[ianconsolata]

This info is displayed in the metamask history, so maybe it's not necessary to have in the UI