Added constant transform randomizer

Randomizer is useful to reset a scene's gameobjects each frame

com.unity.perception/Runtime/Randomization/Randomizers/RandomizerExamples/Randomizers/ConstantTransformRandomizer.cs

+using System;
+using UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers.Tags;
+
+namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers
+{
+    /// <summary>
+    /// Sets a gameobject tagged with <see cref="ConstantTransformRandomizerTag"/> to the same transform(location, rotation, scale)
+    /// each frame. This randomizer is useful to reset a scene to a start state, especially when used in conjunction
+    /// with other randomizers that may move a gameobject.
+    /// </summary>
+    [Serializable]
+    [AddRandomizerMenu("Perception/Constant Transform Randomizer")]
+    public class ConstantTransformRandomizer : Randomizer
+    {
+        /// <inheritdoc/>
+        protected override void OnIterationStart()
+        {
+            var taggedObjects = tagManager.Query<ConstantTransformRandomizerTag>();
+            foreach (var taggedObject in taggedObjects)
+            {
+                var tag = taggedObject.GetComponent<ConstantTransformRandomizerTag>();
+                taggedObject.transform.position = tag.position;
+                taggedObject.transform.rotation = tag.rotation;
+                taggedObject.transform.localScale = tag.scale;
+            }
+        }
+    }
+}

com.unity.perception/Runtime/Randomization/Randomizers/RandomizerExamples/Randomizers/ConstantTransformRandomizer.cs.meta

+fileFormatVersion: 2
+guid: 6a2bb7db515c4b8bb95327b2ef6f3759
+timeCreated: 1611261464

com.unity.perception/Runtime/Randomization/Randomizers/RandomizerExamples/Tags/ConstantTransformRandomizerTag.cs

+namespace UnityEngine.Experimental.Perception.Randomization.Randomizers.SampleRandomizers.Tags
+{
+    /// <summary>
+    /// Tag to indicate which gameobjects should have the effects of <see cref="ConstantTransformRandomizer"/> applied
+    /// to them.
+    /// </summary>
+    [AddComponentMenu("Perception/RandomizerTags/Constant Transform Randomizer Tag")]
+    public class ConstantTransformRandomizerTag : RandomizerTag
+    {
+        public Vector3 position = Vector3.zero;
+        public Quaternion rotation;
+        public Vector3 scale = Vector3.one;
+    }
+}

com.unity.perception/Runtime/Randomization/Randomizers/RandomizerExamples/Tags/ConstantTransformRandomizerTag.cs.meta

+fileFormatVersion: 2
+guid: 4577b7dd026b4d69b2077ac01df61342
+timeCreated: 1611261493