Move round-robin ranking calculation to the manager

[Drarig29]

The viewer should not have much logic. It should just display data created by the manager.

So round-robin ranking calculation should go in the manager's get module. Just as the standings.

brackets-viewer.js/src/helpers.ts

Lines 180 to 193 in 5bdcdaa

	export function getRanking(matches: Match[], formula?: RankingFormula): Ranking {
	formula = formula || (
	(item: RankingItem): number => 3 * item.wins + 1 * item.draws + 0 * item.losses
	);
	const rankingMap: RankingMap = {};
	for (const match of matches) {
	processParticipant(rankingMap, formula, match.opponent1, match.opponent2);
	processParticipant(rankingMap, formula, match.opponent2, match.opponent1);
	}
	return createRanking(rankingMap);
	}

Related: Drarig29/brackets-manager.js#69 Drarig29/brackets-manager.js#72