Experimental undo and redo Python prototype (#1539)

* Experimental undo and redo Python prototype

* Simplify history, use transaction jargon, use walk for more robust serialisation

* Black file, set history size, add file reference to entity_instance constructor

* Ensure that files are always passed when entities are wrapped

* Add support for undo/redo of all project module operations

* Minor fix

* Blender to IFC mappings are now managed by Blender RNA, so they don't break on undo operations. See #1475.

* Implement undo for all attribute operations. See #1475.

* Update documentation for installation of add-on

* Revert Blender RNA approach for Blender-IFC mappings, because it didn't scale, but still fix the undo/redo object memory corruption with new "reload_linked_elements" method.

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

@@ -5,6 +5,19 @@ import blenderbim.bim.import_ifc as import_ifc
 from blenderbim.bim.ifc import IfcStore
 
 
+class ValidateIfcFile(bpy.types.Operator):
+    bl_idname = "bim.validate_ifc_file"
+    bl_label = "Validate IFC File"
+
+    def execute(self, context):
+        import ifcopenshell.validate
+
+        logger = logging.getLogger("validate")
+        logger.setLevel(logging.DEBUG)
+        ifcopenshell.validate.validate(IfcStore.get_file(), logger)
+        return {"FINISHED"}
+
+
 class ProfileImportIFC(bpy.types.Operator):
     bl_idname = "bim.profile_import_ifc"
     bl_label = "Profile Import IFC"