New add application usecase, improved add_classification usecase and better defaults for owner settings. Thanks johltn

src/ifcopenshell-python/ifcopenshell/api/owner/add_application.py

@@ -0,0 +1,9 @@
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"attributes": None}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        return self.file.create_entity("IfcApplication", **self.settings["attributes"])

src/ifcopenshell-python/ifcopenshell/api/owner/settings.py

@@ -1,10 +1,13 @@
+# Note: it is the intent for you to override these with your own functions
+
+
 def get_person(ifc):
-    pass
+    return ifc.by_type("IfcPerson")[0]
 
 
 def get_organisation(ifc):
-    pass
+    return ifc.by_type("IfcOrganization")[0]
 
 
 def get_application(ifc):
-    pass
+    return ifc.by_type("IfcApplication")[0]