Allow for combination of both handlers

[Jan-DT]

Currently, there is two available handlers: the COMMAND_TO_SERVER handler, and the REGULAR handler. The problem is that, when using the REGULAR handler, you loose the ability to load balance servers. It would be nice to have a combination between the two, where you would do something like:

many-to-many-handler {
    command {
        # Commands that can be used
        commands=[
            lobby,
            hub
        ]
        # List of servers
        servers=[
            lobby,
            lobby1,
            hub
        ]
        # Send Mode Formula
        # RANDOM: It will send the player to a random server among the configured ones
        # FIRST_AVAILABLE: It will send the player to the first available server
        # EMPTIEST: Send the player to the server with the least amount of players
        send-mode=RANDOM
    }

    command {
        # Commands that can be used
        commands=[
            bedwars,
            bw
        ]
        # List of servers
        servers=[
            bedwars1,
            bedwars2
        ]
        # Send Mode Formula
        # RANDOM: It will send the player to a random server among the configured ones
        # FIRST_AVAILABLE: It will send the player to the first available server
        # EMPTIEST: Send the player to the server with the least amount of players
        send-mode=EMPTIEST
    }
}