Add "No Repeated Pairs" option

[giunto]

Sometimes when rotating devs, the same dev pairing from the last rotation will stay even if those devs are not sticking. Since randomness is not always unique, I would like to add a feature that ensures that the next rotation will not contain any of the same pairs from the previous rotation (if possible).

This option will be toggled within the options menu. As part of this, a new category called "Pairing options" will be added that contains the No Repeat option and the Allow Solo options.

The functionality should account for sticking pairs, and whether there are enough devs in rotation to have a unique pair, since there will be scenarios where this option isn't possible.

Should the functionality check the pairings from the last rotation, or should it check the pairings that were first loaded in the browser? I was planning on doing the former, but I think from our teams perspective it would be better to only compare against the rotations that were loaded the first time. That way, if we rotate and there's a pair that someone isn't satisfied with we can rotate again and ensure the next pairings are still unique from who actually paired when we decided pairs last. That only works because we only open and close rotato when deciding on pairs. I'm not sure if that would work for other teams, or if it would be confusing to handle them that way.