add units support in float, double and Float3 input

Source/Editor/Utilities/Units.cs

@@ -0,0 +1,9 @@
+namespace FlaxEditor.Utilities;
+
+public class Units
+{
+    /// <summary>
+    /// Factor of units per meter.
+    /// </summary>
+    public static readonly float Meters2Units = 100f;
+}