Add Team Limited/Team Constructed events

It was announced that there will be a Team Trios Pro Tour in 2018, as well as an increase in team Grand Prix and team PTQs. It seems like it would be a great option to have on xmage.

Team Constructed:
*Each team member will play the opposing team member with the same player designation (A, B, or C).
*Allow for mixed format (ie, standard/modern/legacy)
*Allow for unified construction rules (no overlapping non-basic cards between decks on a team).
*A team wins the overall match by winning 2 individual matches.

Team Draft:
*Team members draft at the same draft table with one opposing team (6 total players per draft table). *Team members will be seated at the draft table in exactly the following order:
Team 1, Player A
Team 2, Player C
Team 1, Player B
Team 2, Player A
Team 1, Player C
Team 2, Player B
*No communication between teammates during the draft (not really enforcable, but could mute chat until draft is over)
*For Grand Prix, each team member will play the opposing team member with the same player designation (A, B, or C).
*For casual team draft, round robin play for each player against each opposing team member.
*A team wins the overall match by winning a majority of the games played (ie, 5 of 9 possible matches for round robin play).

Team Sealed:
*12 boosters for a team of 3
*Each team member will play the opposing team member with the same player designation (A, B, or C).
*All cards must be assigned to a player's deck or sideboard and can not be transferred between players during the tournament.