Ghost Roles (#3106)

* Add files for Ghost Roles.

* Work on Ghost Roles

* Improvements

* GHOST ROLES IS DONE

* mmm yes

* auto-update when setting rolename/roledescription

* well

* command graceful error

* Makes UI have a scrollbar when it has too many entries

* fix command fuckup

* Apply suggestions from code review

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Content.Shared/GameObjects/Components/Observer/GhostRolesEuiMessages.cs

@@ -0,0 +1,41 @@
+using System;
+using Content.Shared.Eui;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Observer
+{
+    [NetSerializable, Serializable]
+    public struct GhostRoleInfo
+    {
+        public uint Identifier { get; set; }
+        public string Name { get; set; }
+        public string Description { get; set; }
+    }
+
+    [NetSerializable, Serializable]
+    public class GhostRolesEuiState : EuiStateBase
+    {
+        public GhostRoleInfo[] GhostRoles { get; }
+
+        public GhostRolesEuiState(GhostRoleInfo[] ghostRoles)
+        {
+            GhostRoles = ghostRoles;
+        }
+    }
+
+    [NetSerializable, Serializable]
+    public class GhostRoleTakeoverRequestMessage : EuiMessageBase
+    {
+        public uint Identifier { get; }
+
+        public GhostRoleTakeoverRequestMessage(uint identifier)
+        {
+            Identifier = identifier;
+        }
+    }
+
+    [NetSerializable, Serializable]
+    public class GhostRoleWindowCloseMessage : EuiMessageBase
+    {
+    }
+}