Allow OP to choose a winning suggestion

[hannahkane]

Acceptance tests:

• [x] Only OP can choose the winner
• [x] Winning suggestion is displayed first, and marked as the winner
• [x] Other users can continue to suggest once a winner has been chosen
• [x] If OP chooses a new winner, the previous winner is no longer marked as such

[hannahkane]

I'm #1! I'm #1!

[hannahkane]

Donezo Washington