Add method to reconstruct SFG from a schedule

Closes #239 (closed)

Adds the method _reintroduce_delays() to Schedule, which looks through the laps for the signals in the schedule and inserts delay elements accordingly.

Also adds the method SFG.simplify_delay_element_placement() which looks through the neighbors of each delay element in order to simplify the sfg and reduce the total number of delay elements.

The Schedule.sfg property now returns an sfg reconstructed using the above functions, instead of the original sfg.

b_asic/signal_flow_graph.py

@@ -737,11 +737,12 @@ class SFG(AbstractOperation):
         return sfg_copy()
 
     def simplify_delay_element_placement(self) -> "SFG":
-        """ Simplify an SFG by removing some redundant delay elements.
-            For example two signals originating from the same starting point, each
-            connected to a delay element will combine into a single delay element.
+        """
+        Simplify an SFG by removing some redundant delay elements.
+        For example two signals originating from the same starting point, each
+        connected to a delay element will combine into a single delay element.
 
-            Returns a copy of the simplified SFG.
+        Returns a copy of the simplified SFG.
         """
 
         sfg_copy = self()