Device network as ecs (#4205)

* Work on DeviceNetworkSystem

* Implement device networking as ecs
Remove mailing unit code for now
Remove device network metadata

* Implement integration tests for device networking

* Remove manual updating DeviceNetworkSystem and use WaitRunTicks

* Fix wrong component name in ignored components

* Apply suggestions from code review

Co-authored-by: mirrorcult <notzombiedude@gmail.com>

* Rename NetworkUtils to DeviceNetworkConstants
Change connection type constants to enum
Remove create function from network payload class

* Change broken nodegroup check in wirenet to grid check

* Change ComponentManager to entity manager in DeviceNetworkSystem

* Fix smaller mistakes

* Wtf random test fail pls run them again smh

* Fix DataField in DeviceNetworkComponent

* Fix yaml in DeviceNetworkTest

* Fix DeviceNetworkComponent DeviceNetId property

Co-authored-by: Julian Giebel <j.giebel@netrocks.info>
Co-authored-by: mirrorcult <notzombiedude@gmail.com>

Content.Server/DeviceNetwork/DeviceNetworkConstants.cs

@@ -0,0 +1,21 @@
+namespace Content.Server.DeviceNetwork
+{
+    /// <summary>
+    /// A collection of utilities to help with using device networks
+    /// </summary>
+    public static class DeviceNetworkConstants
+    {
+        public enum ConnectionType
+        {
+            Private,
+            Wired,
+            Wireless
+        }
+
+        /// <summary>
+        /// The key for command names
+        /// E.g. [DeviceNetworkConstants.Command] = "ping"
+        /// </summary>
+        public const string Command = "command";
+    }
+}