Added new ComponentEvents system in IEventBus. (#1601)

* Added new ComponentEventBus, combined it with IEventBus.

* Removed all traces of IEntity from ComponentDependencies.
Removed IEntityManager dependency from ComponentManager.

* Added entity create/delete events to IEntityManager.

* ComponentEvents now use EntitySystemMessages instead of their custom ComponentEvent class.

* Component events are now just overloads of entity events.

* Removed obsolete EntitySystemMessage, now everything uses the base EntityEventArgs.

* Add a bool argument for if the message should be broadcast as well as directed.
Fix ordering and init issues of events in EntityManager.

* Changed names from Component/Entity events to Directed/Broadcast.

* Fix bugs and unit tests.

Robust.Client/GameObjects/EntitySystems/ClientOccluderSystem.cs

@@ -106,7 +106,7 @@ namespace Robust.Client.GameObjects
     /// <summary>
     ///     Event raised by a <see cref="ClientOccluderComponent"/> when it needs to be recalculated.
     /// </summary>
-    internal sealed class OccluderDirtyEvent : EntitySystemMessage
+    internal sealed class OccluderDirtyEvent : EntityEventArgs
     {
         public OccluderDirtyEvent(IEntity sender, (GridId grid, Vector2i pos)? lastPosition, SnapGridOffset offset)
         {

Robust.Client/GameObjects/EntitySystems/InputSystem.cs

@@ -157,7 +157,7 @@ namespace Robust.Client.GameObjects
     /// <summary>
     ///     Entity system message that is raised when the player changes attached entities.
     /// </summary>
-    public class PlayerAttachSysMessage : EntitySystemMessage
+    public class PlayerAttachSysMessage : EntityEventArgs
     {
         /// <summary>
         ///     New entity the player is attached to.