ChangeModesOperation needs to send a notification that updates player fight/chase modes.

[sean-owen]

Copied over from jlnunez89/fibula-mmo#75 (comment)

Problem:

Currently, when a ChangeModesOperation is executed, the player who's fight and chase modes changed is not made aware of the changes, essentially desynchronizing the modes seen in the client.

Solution:

1. Create a new outgoing packet for OutgoingGamePacketType.PlayerModes under the namespace/folder Fibula.Communications.Packets.Outgoing:

   /// <summary>
   /// Updates a player's modes.
   /// </summary>
   PlayerModes = 0xA7,
   

2. Create a new packet writer under the namespace/folder Fibula.Protocol.V772.PacketWriters for that new packet.

3. Hook up the new packet writer in Fibula.Protocol.V772.CompositionRootExtensions class.

4. Finally, in ChangeModesOperation.Execute, add a new notification that sends the new packet to the player, to update their modes.

[sean-owen]

https://github.com/Fibula-MMO/fibula-server/blob/master/src/Fibula.Mechanics/Operations/ChangeModesOperation.cs

@jlnunez89 I decided to try and have a crack at this issue. Initially familiarizing myself with the solution & projects and I do have a question - info below.

Looking at the Execute method of the ChangeModesOperation.cs, snippet below, and I am trying to understand:

1. Why is assignment of combatantCreature.SafeMode commented out?

protected override void Execute(IOperationContext context)
       {
           var onCreature = this.GetRequestor(context.CreatureFinder);

           if (onCreature == null || !(onCreature is ICombatant combatantCreature))
           {
               return;
           }

           context.Logger.Debug($"{onCreature.Name} changed modes to {this.FightMode} and {this.ChaseMode}, safety: {this.IsSafeModeOn}.");

           combatantCreature.FightMode = this.FightMode;
           combatantCreature.ChaseMode = this.ChaseMode;

           if (this.ChaseMode == ChaseMode.Chase && combatantCreature.AutoAttackTarget != null)
           {
               combatantCreature.SetFollowTarget(combatantCreature.AutoAttackTarget);
           }
           else if (this.ChaseMode == ChaseMode.Stand)
           {
               combatantCreature.SetFollowTarget(null);
           }

           /* combatantCreature.SafeMode = this.IsSafeModeOn; */
       }