More improvements to Infrastructure

• Renamed MPI_Call to MPICall
  • in Python it is a good practice to use CamelCase for class names
• fix instruction block generating if for empty branch
• InstructionBlock returns empty list instead of exception when qurey for empty branch
• TemplateManager can now insert blocks before or after given one

scripts/Infrastructure/InstructionBlock.py

@@ -131,6 +131,8 @@ class InstructionBlock:
             str: The operation specified by kind and index
         """
         if index == 'all':
+            if kind not in self.operations:
+                return []
             return self.operations[kind]
         else:
             as_int = int(index)  # will Raise ValueError if not integer