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.Server/GameObjects/Components/Observer/GhostRoleMobSpawnerComponent.cs

@@ -0,0 +1,69 @@
+using System;
+using Content.Server.GameObjects.Components.Mobs;
+using Content.Server.Players;
+using JetBrains.Annotations;
+using Robust.Server.Interfaces.GameObjects;
+using Robust.Server.Interfaces.Player;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Serialization;
+using Robust.Shared.ViewVariables;
+
+namespace Content.Server.GameObjects.Components.Observer
+{
+    /// <summary>
+    ///     Allows a ghost to take this role, spawning a new entity.
+    /// </summary>
+    [RegisterComponent, ComponentReference(typeof(GhostRoleComponent))]
+    public class GhostRoleMobSpawnerComponent : GhostRoleComponent
+    {
+        public override string Name => "GhostRoleMobSpawner";
+
+
+        [ViewVariables]
+        private bool _deleteOnSpawn = true;
+
+        [ViewVariables(VVAccess.ReadWrite)]
+        private int _availableTakeovers = 1;
+
+        [ViewVariables]
+        private int _currentTakeovers = 0;
+
+        [CanBeNull, ViewVariables(VVAccess.ReadWrite)] public string Prototype { get; private set; }
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+
+            serializer.DataField(this, x => x.Prototype, "prototype", null);
+            serializer.DataField(ref _deleteOnSpawn, "deleteOnSpawn", true);
+            serializer.DataField(ref _availableTakeovers, "availableTakeovers", 1);
+        }
+
+        public override bool Take(IPlayerSession session)
+        {
+            if (Taken)
+                return false;
+
+            if(string.IsNullOrEmpty(Prototype))
+                throw new NullReferenceException("Prototype string cannot be null or empty!");
+
+            var mob = Owner.EntityManager.SpawnEntity(Prototype, Owner.Transform.Coordinates);
+
+            mob.EnsureComponent<MindComponent>();
+            session.ContentData().Mind.TransferTo(mob);
+
+            if (++_currentTakeovers < _availableTakeovers) return true;
+
+            Taken = true;
+
+            if (_deleteOnSpawn)
+                Owner.Delete();
+
+
+            return true;
+
+        }
+    }
+}