Mortician's Menagerie (#2391)

* Body bags!

* Morgue Trays and the Crematorium!
Reorganised body bags to be under Morgue, not Medical

* Fix. Things outside of EntityStorageComponents now use the Try*Storage() not just *Storage() methods - Allows mobs to be trapped in a morgue/crematorium whose tray can't open.

* Fix tests. Modernise component dependency and nullability.

* Update Content.Server/GameObjects/Components/Morgue/MorgueTrayComponent.cs

Co-authored-by: Víctor Aguilera Puerto <6766154+Zumorica@users.noreply.github.com>

Content.Shared/GameObjects/Components/Storage/SharedMorgue.cs

@@ -0,0 +1,26 @@
+using System;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Morgue
+{
+    [Serializable, NetSerializable]
+    public enum MorgueVisuals
+    {
+        Open,
+        HasContents,
+        HasMob,
+        HasSoul,
+    }
+
+    [Serializable, NetSerializable]
+    public enum CrematoriumVisuals
+    {
+        Burning,
+    }
+
+    [Serializable, NetSerializable]
+    public enum BodyBagVisuals
+    {
+        Label,
+    }
+}