Incomplete: updaing py AL to include grouping
Added utility Python function for spliting a string into an array of
strings
Utilities: Add new group controller

Added a new class for group controller such that the state is saved
for each iteration with a new group column. The column is set to a
sentinel value if no grouping option is provided.
Reverted control.py_in
Added grouping support in py AL
Made output table compatible with grouping

Added validation for grouping column names
Updated py AL to accept groups as a list instead of string
Fixed IGD final function error