Indexed domain kernel

This MR introduces the possibility to introduce sp.IndexedBase objects in the kernel that form an outer loop for indexing the arrays in the inner loops

pystencils/transformations.py

@@ -156,7 +156,6 @@ def get_common_indexed(set_of_indexed):
         If the sympy.Indexed have different shapes ValueError is raised"""
 
 
-
 def make_loop_over_domain(body, iteration_slice=None, ghost_layers=None, loop_order=None):
     """Uses :class:`pystencils.field.Field.Access` to create (multiple) loops around given AST.