Refactor SpeciesUI into overlay and status effects (#381)

* Refactor SpeciesUI into overlay and status effects

All components that update the UI will need to use PlayerAttached for cases where the Mind transfers I think.

* Change overlay / status effects to use states

* Change TryRemoveStatus to RemoveStatus

Doesn't return a bool so not trying.
Addressing PJB's feedback.

Content.Shared/GameObjects/Components/Mobs/SharedStatusEffectsComponent.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Mobs
+{
+    /// <summary>
+    /// Handles the icons on the right side of the screen.
+    /// Should only be used for player-controlled entities
+    /// </summary>
+    public abstract class SharedStatusEffectsComponent : Component
+    {
+        public override string Name => "StatusEffectsUI";
+        public override uint? NetID => ContentNetIDs.STATUSEFFECTS;
+        public sealed override Type StateType => typeof(StatusEffectComponentState);
+
+    }
+
+    [Serializable, NetSerializable]
+    public class StatusEffectComponentState : ComponentState
+    {
+        public Dictionary<StatusEffect, string> StatusEffects;
+
+        public StatusEffectComponentState(Dictionary<StatusEffect, string> statusEffects) : base(ContentNetIDs.STATUSEFFECTS)
+        {
+            StatusEffects = statusEffects;
+        }
+    }
+
+    // Each status effect is assumed to be unique
+    public enum StatusEffect
+    {
+        Health,
+    }
+}