Disposal mailing (#2194)

* Implement device networking

* Implement device configuration menu

* Fix device network

* Implement disposal mailing unit

* Implement base network connection
Implement wired and wireless network connection
Implement device network metadata

* Fix dereference null error

* Fix wired network null checks

* Change BaseNetworks enum to NetworkUtils class
Add PingResponse function to NetworkUtils
Change device network file structure

* Add doc comments

* Apply suggestions from code review

Co-authored-by: DrSmugleaf <DrSmugleaf@users.noreply.github.com>

* Add tag validation to disposal mailing unit

* Add tag validation to the mailing unit component

* Address reviews
Change WiredNetwork can connect check
Change device networking string literals to constants

* Address reviews
Revert changes to PowerProvider and PowerReceiver
Add new NodeGroup
WELP

* Fix recursive access to Owner property

* Integrate suggested changes

* Fix TryGetWireNet acting on NullPowerProvider
Fix network connections not checking if their owner has been deleted

* Close device network connection when the owning entity got deleted
Fix mailing unit not closing the device network connection on remove

* Remove GetWireNet from NullPowerProvider

Co-authored-by: Julian Giebel <j.giebel@netrocks.info>
Co-authored-by: DrSmugleaf <DrSmugleaf@users.noreply.github.com>

Content.Server/DeviceNetwork/Metadata.cs

@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Content.Server.GameObjects.EntitySystems.DeviceNetwork
+{
+    public class Metadata : Dictionary<string, object>
+    {
+        public bool TryParseMetadata<T>(string key, [NotNullWhen(true)] out T data)
+        {
+            if(TryGetValue(key, out var value) && value is T typedValue)
+            {
+                data = typedValue;
+                return true;
+            }
+
+            data = default;
+            return false;
+        }
+    }
+}