Improve user contributed notes voting mechanism

[DrewAPicture]

In #1649, we've been discussing user contributed notes UX, which covers both the voting mechanism and how we list/sort notes. This ticket splits off the proposed voting mechanism changes.

[keesiemeijer]

To move both tickets along there should be some consensus about the voting process.

Use Reddit style voting (clicking twice to cancel your vote) or clicking the opposite to cancel the vote. Or leave it as it's now. See the discussion in #1649.

Other things to think about is if we should allow users to vote on their own notes (as it's now), and if the voting buttons should be shown (or disabled) on comments that are in moderation.

[keesiemeijer]

Disable voting on your own submitted notes

[coffee2code]

In 3753:

developer.wordpress.org: Prevent user from voting on their own user contributed note.

Props keesiemeijer.
See #1755.

[coffee2code]

I am in favor of Reddit-style voting. Voting up or down registers that particular vote. In order to remove an existing vote without casting the opposite vote, the user can click on the vote again to toggle it.

Or stated another way:

• Clicking a vote arrow toggles the state of that particular vote.
• If the state is being toggled "on", then the state of the opposite vote becomes (or stays) "off".

[keesiemeijer]

Add Reddit-style voting.

[keesiemeijer]

The 1755.1.patch​ adds Reddit-style voting without disabling the opposite vote (as was implemented in 1649.2.patch). I will create another patch for Reddit-style voting with the opposite voting button disabled.

[keesiemeijer]

Add Reddit-style voting with the opposite voting button disabled

[coffee2code]

In 3786:

developer.wordpress.org: Implement Reddit-style voting changes to user contributed notes.

Permits user to un-cast their vote by clicking their vote arrow a second time. Previously a vote could only be changed but not unset.

Props keesiemeijer.
Fixes #1755.