Convert familiars to GhostRoleMobSpawner (#9525)

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

Content.Server/Ghost/Roles/Events/GhostRoleSpawnerUsedEvent.cs

@@ -0,0 +1,25 @@
+namespace Content.Server.Ghost.Roles.Events
+{
+    /// <summary>
+    /// Raised on a spawned entity after they use a ghost role mob spawner.
+    /// </summary>
+    public sealed class GhostRoleSpawnerUsedEvent : EntityEventArgs
+    {
+        /// <summary>
+        /// The entity that spawned this.
+        /// </summary>
+        public EntityUid Spawner;
+
+        /// <summary>
+        /// The entity spawned.
+        /// </summary>
+        public EntityUid Spawned;
+
+        public GhostRoleSpawnerUsedEvent(EntityUid spawner, EntityUid spawned)
+        {
+            Spawner = spawner;
+
+            Spawned = spawned;
+        }
+    }
+}