add layerMaskModifier to be able to set vector feature visuals' unity layers

Author: brnkhy

Runtime/Mapbox/VectorModule/MeshGeneration/GameObjectModifiers/LayerMaskModifier.cs

@@ -0,0 +1,25 @@
+using System;
+using Mapbox.BaseModule.Map;
+using Mapbox.BaseModule.Utilities;
+using UnityEngine;
+using UnityEngine.Serialization;
+
+namespace Mapbox.VectorModule.MeshGeneration.GameObjectModifiers
+{
+    [Serializable]
+    public class LayerMaskModifier : GameObjectModifier
+    {
+        //I couldn't get LayerMask to work here
+        private int _layerMask;
+
+        public LayerMaskModifier(int layerMask)
+        {
+            _layerMask = layerMask;
+        }
+
+        public override void Run(VectorEntity ve, IMapInformation mapInformation)
+        {
+            ve.GameObject.layer = _layerMask;
+        }
+    }
+}

Runtime/Mapbox/VectorModule/MeshGeneration/GameObjectModifiers/LayerMaskModifier.cs.meta

@@ -0,0 +1,19 @@
+using Mapbox.BaseModule.Unity;
+using Mapbox.VectorModule.MeshGeneration.Unity;
+using UnityEngine;
+
+namespace Mapbox.VectorModule.MeshGeneration.GameObjectModifiers
+{
+    [CreateAssetMenu(menuName = "Mapbox/Modifiers/LayerMask Modifier")]
+    public class LayerMaskModifierObject : ScriptableGameObjectModifierObject
+    {
+        public int LayerMask;
+        private LayerMaskModifier _prefabModifierImplementation;
+        protected override GameObjectModifier _gameObjectModifierImplementation => _prefabModifierImplementation;
+
+        public override void ConstructModifier(UnityContext unityContext)
+        {
+            _prefabModifierImplementation = new LayerMaskModifier(LayerMask);
+        }
+    }
+}