voting with optional vote data contributions

[nothub]

Make the data contribution for the vote comparison feature optional, while still allow users to vote.
To accomplish this, if a user opts out of the data contribution mechanisms, store the voting data locally instead.

This way unidentified voters are still able to use most of the applications features and the data quality of the other users vote comparison is not at risk ☺️

[nothub]

On second thought, this could also reduce an implicit chilling effect for voters to use your app, that are less technically capable and do not know the details of hashing and encryption of their phone number.