Revert "Minor fix - remove redundant code"

This reverts commit 7828508179.

Turned out when I was assuming `bim.add_style` is assigning the style but it wasn't, it was `bim.update_representation` on the file save. So basically during the session style wasn't assigned, therefore I added back explicit style assignment. 😬

src/blenderbim/blenderbim/bim/module/drawing/operator.py

@@ -2624,6 +2624,9 @@ class AddReferenceImage(bpy.types.Operator, Operator):
         obj.material_slots[0].material = material
         bpy.ops.bim.add_style()
 
+        style = ifc_file.by_id(material.BIMMaterialProperties.ifc_style_id)
+        tool.Style.assign_style_to_object(style, obj)
+
         material.diffuse_color = (0.031379, 0, 0.801157, 1)
         material.BIMStyleProperties.diffuse_path = self.filepath
         material.BIMStyleProperties.uv_mode = "Generated"

src/blenderbim/blenderbim/tool/style.py

@@ -506,3 +506,9 @@ class Style(blenderbim.core.tool.Style):
             else:
                 items.append(item)
         return items
+
+    @classmethod
+    def assign_style_to_object(cls, style, obj):
+        """assigns `style` to `object` current representation"""
+        representation = tool.Geometry.get_active_representation(obj)
+        tool.Ifc.run("style.assign_representation_styles", shape_representation=representation, styles=[style])