Feature/remove per player hologram

[RealGatt]

This PR adds two new methods.

    /**
     *
     * @param targetPlayer The target player
     * @return object instance
     * @author Gatt
     */
    NPC removePlayerLines(Player targetPlayer);
    /**
     *
     * @param targetPlayer The target player
     * @param update whether or not to update the hologram
     * @return object instance
     * @author Gatt
     */
    NPC removePlayerLines(Player targetPlayer, boolean update);

Allows for the removal of player-specific lines, as requested in the Discord.

[JitseB]

What's the need to have a method for this built in? Setting the new lines equal to an empty list does the job just as well by the looks of it.

[RealGatt]

Due to the way that player-specific lines are grabbed, if you were to set a player's lines to an empty list, it would display nothing for that users' hologram. See the getPlayerLines(Player player) method.

Currently there is no way of actually removing player-specific lines, which allows it to effectively be reset to the holograms' original lines.

[JitseB]

Merging PR!