First attempt at ripping out agnostic code into ifcopenshell.api namespace. See #1399.

src/ifcopenshell-python/ifcopenshell/api/sequence/data.py

@@ -0,0 +1,15 @@
+class Data:
+    is_loaded = False
+    tasks = {}
+
+    @classmethod
+    def purge(cls):
+        cls.is_loaded = False
+        cls.tasks = {}
+
+    @classmethod
+    def load(cls, file):
+        cls.tasks = {}
+        for task in file.by_type("IfcTask"):
+            cls.tasks[task.id()] = {"Name": task.Name, "Identification": task.Identification or ""}
+        cls.is_loaded=True