stretch for scatter too (#396)

just copy the way details do it

NewHorizons/Builder/Props/ScatterBuilder.cs

@@ -69,6 +69,7 @@ namespace NewHorizons.Builder.Props
                 var detailInfo = new PropModule.DetailInfo()
                 {
                     scale = propInfo.scale,
+                    stretch = propInfo.stretch,
 					keepLoaded = propInfo.keepLoaded
                 };
                 var scatterPrefab = DetailBuilder.Make(go, sector, prefab, detailInfo);

NewHorizons/External/Modules/PropModule.cs

@@ -123,7 +123,12 @@ namespace NewHorizons.External.Modules
             /// <summary>
             /// Scale this prop once it is placed
             /// </summary>
-            public float scale = 1f;
+            [DefaultValue(1f)] public float scale = 1f;
+
+            /// <summary>
+            /// Scale each axis of the prop. Overrides `scale`.
+            /// </summary>
+            public MVector3 stretch;
 
             /// <summary>
             /// The number used as entropy for scattering the props

NewHorizons/Schemas/body_schema.json

@@ -1376,7 +1376,12 @@
         "scale": {
           "type": "number",
           "description": "Scale this prop once it is placed",
-          "format": "float"
+          "format": "float",
+          "default": 1.0
+        },
+        "stretch": {
+          "description": "Scale each axis of the prop. Overrides `scale`.",
+          "$ref": "#/definitions/MVector3"
         },
         "seed": {
           "type": "integer",