Add ContainerComp (#31311)

Applies EntProtoId changes upon insertion / removal from container. Can also be useful for borgs / mechs / vehicles in future but atm I just used it for AI.

Content.Shared/Containers/ContainerCompComponent.cs

@@ -0,0 +1,17 @@
+using Robust.Shared.GameStates;
+using Robust.Shared.Prototypes;
+
+namespace Content.Shared.Containers;
+
+/// <summary>
+/// Applies container changes whenever an entity is inserted into the specified container on this entity.
+/// </summary>
+[RegisterComponent, NetworkedComponent]
+public sealed partial class ContainerCompComponent : Component
+{
+    [DataField(required: true)]
+    public EntProtoId Proto;
+
+    [DataField(required: true)]
+    public string Container = string.Empty;
+}