Merge pull request #635 from kianzarrin/625-boost-lane-hover-hitpos

#625:
revived the lane hovering code from Traffic ++
Lane Connector now highlights lanes with Lane Sheath overlay.
Train markers use right color.
embolden lane curves for selected lane.
fixed drawing lane curves underground
made performance optimization by caching mouse pointer and lane bounds. They are recalculated only if user moves the mouse ray.
#543: I fixed the vertical mismatch by intersecting the mouse ray at the place where it hits the road.

Author: kianzarrin

TLM/TLM/UI/SubTool.cs

@@ -1,7 +1,6 @@
 namespace TrafficManager.UI {
     using ColossalFramework.UI;
     using JetBrains.Annotations;
-    using TrafficManager.UI.Textures;
     using UnityEngine;
 
     public abstract class SubTool {
@@ -78,6 +77,10 @@ private Texture2D BorderlessTexture {
 
         private GUIStyle borderlessStyle_;
 
+        protected virtual Vector3 HitPos => TrafficManagerTool.HitPos;
+
+        protected virtual Vector3 MousePosition => MainTool.MousePosition;
+
         protected virtual ushort HoveredNodeId {
             get => TrafficManagerTool.HoveredNodeId;
             set => TrafficManagerTool.HoveredNodeId = value;

TLM/TLM/UI/SubTools/LaneArrowTool.cs

@@ -187,7 +187,6 @@ protected override ushort HoveredNodeId {
                 }
                 return base.HoveredNodeId;
             }
-            set => base.HoveredNodeId = value;
         }
 
         /// <summary>