cleanup adapters (#148)

Author: wpbonelli

flopy4/discretization/structured_grid.py renamed to flopy4/adapters.py

@@ -12,9 +12,8 @@
 from attrs import define
 from flopy.discretization import StructuredGrid
 
-from flopy4.discretization.structured_grid import StructuredGridWrapper
-
-from .grid_utils import get_coords
+from flopy4.adapters import StructuredGridWrapper
+from flopy4.mf6.utils.grid_utils import get_coords
 
 
 @define

flopy4/mf6/interface/flopy3.py renamed to flopy4/mf6/adapters.py

@@ -5,9 +5,9 @@
 from flopy.discretization import StructuredGrid
 from flopy.discretization.modeltime import ModelTime
 
+from flopy4.mf6.adapters import Flopy3Model, Flopy3Package
 from flopy4.mf6.gwf import Chd, Dis, Gwf, Ic, Npf, Oc
 from flopy4.mf6.ims import Ims
-from flopy4.mf6.interface.flopy3 import Flopy3Model, Flopy3Package
 from flopy4.mf6.simulation import Simulation
 from flopy4.mf6.tdis import Tdis