feat: add PLAYER_EVENT_ON_CAN_JOIN_LFG

[r-o-b-o-t-o]

Adds a new Player event:

PLAYER_EVENT_ON_CAN_JOIN_LFG = 50, // (event, player, roles, dungeons, comment) - Can return false to prevent queueing

Example Lua snippet:

local PLAYER_EVENT_ON_CAN_JOIN_LFG = 50

RegisterPlayerEvent(PLAYER_EVENT_ON_CAN_JOIN_LFG, function(event, player, roles, dungeons, comment)
	print("Player: " .. player:GetName())
	print("Roles: " .. tostring(roles))
	print("Dungeons:")
	for i = 1, #dungeons do
		print(dungeons[i])
	end
	if (comment ~= nil) then
		print("Comment: " .. comment)
	end

	return false -- prevent queueing
end)