Adds Network Resource Uploading for admins. (#6904)

Co-authored-by: Pieter-Jan Briers <pieterjan.briers@gmail.com>
Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

Content.Shared/Administration/NetworkResourceUploadMessage.cs

@@ -0,0 +1,39 @@
+using Lidgren.Network;
+using Robust.Shared.Network;
+using Robust.Shared.Utility;
+
+namespace Content.Shared.Administration;
+
+public sealed class NetworkResourceUploadMessage : NetMessage
+{
+    public override NetDeliveryMethod DeliveryMethod => NetDeliveryMethod.ReliableUnordered;
+    public override MsgGroups MsgGroup => MsgGroups.Command;
+
+    public byte[] Data { get; set; } = Array.Empty<byte>();
+    public ResourcePath RelativePath { get; set; } = ResourcePath.Self;
+
+    public NetworkResourceUploadMessage()
+    {
+    }
+
+    public NetworkResourceUploadMessage(byte[] data, ResourcePath relativePath)
+    {
+        Data = data;
+        RelativePath = relativePath;
+    }
+
+    public override void ReadFromBuffer(NetIncomingMessage buffer)
+    {
+        var dataLength = buffer.ReadVariableInt32();
+        Data = buffer.ReadBytes(dataLength);
+        RelativePath = new ResourcePath(buffer.ReadString(), buffer.ReadString());
+    }
+
+    public override void WriteToBuffer(NetOutgoingMessage buffer)
+    {
+        buffer.WriteVariableInt32(Data.Length);
+        buffer.Write(Data);
+        buffer.Write(RelativePath.ToString());
+        buffer.Write(RelativePath.Separator);
+    }
+}