Add body part and body manager interfaces (#1939)

* Add body part and body manager interfaces

* Merge fixes

Content.Server/GameObjects/Components/Body/IBodyManagerComponent.cs

@@ -0,0 +1,67 @@
+using System;
+using Content.Server.Body;
+using Content.Server.Body.Network;
+using Content.Shared.GameObjects.Components.Body;
+
+namespace Content.Server.GameObjects.Components.Body
+{
+    // TODO: Merge with ISharedBodyManagerComponent
+    public interface IBodyManagerComponent : ISharedBodyManagerComponent
+    {
+        /// <summary>
+        ///     The <see cref="BodyTemplate"/> that this <see cref="BodyManagerComponent"/>
+        ///     is adhering to.
+        /// </summary>
+        public BodyTemplate Template { get; }
+
+        /// <summary>
+        ///     The <see cref="BodyPreset"/> that this <see cref="BodyManagerComponent"/>
+        ///     is adhering to.
+        /// </summary>
+        public BodyPreset Preset { get; }
+
+        /// <summary>
+        ///     Installs the given <see cref="IBodyPart"/> into the given slot.
+        /// </summary>
+        /// <returns>True if successful, false otherwise.</returns>
+        bool TryAddPart(string slot, IBodyPart part, bool force = false);
+
+        bool HasPart(string slot);
+
+        /// <summary>
+        ///     Ensures that this body has the specified network.
+        /// </summary>
+        /// <typeparam name="T">The type of the network to ensure.</typeparam>
+        /// <returns>
+        ///     True if the network already existed, false if it had to be created.
+        /// </returns>
+        bool EnsureNetwork<T>() where T : BodyNetwork;
+
+        /// <summary>
+        ///     Ensures that this body has the specified network.
+        /// </summary>
+        /// <param name="networkType">The type of the network to ensure.</param>
+        /// <returns>
+        ///     True if the network already existed, false if it had to be created.
+        /// </returns>
+        bool EnsureNetwork(Type networkType);
+
+        /// <summary>
+        ///     Removes the <see cref="BodyNetwork"/> of the given type in this body,
+        ///     if one exists.
+        /// </summary>
+        /// <typeparam name="T">The type of the network to remove.</typeparam>
+        void RemoveNetwork<T>() where T : BodyNetwork;
+
+        /// <summary>
+        ///     Removes the <see cref="BodyNetwork"/> of the given type in this body,
+        ///     if there is one.
+        /// </summary>
+        /// <param name="networkType">The type of the network to remove.</param>
+        void RemoveNetwork(Type networkType);
+
+        void PreMetabolism(float frameTime);
+
+        void PostMetabolism(float frameTime);
+    }
+}