Make h_edge a function of position to have bottom/top/side cooled cells

[DavidMStraub]

Hi,

the title of the discussion is actually a comment in pouch_cell_2D_current_collectors.py. I think this is straightforward to implement, but it would mean replacing h_edge by four paremeters h_edge_top, h_edge_bottom, h_edge_left, h_edge_right. Would this be something you would like to see upstream or would you consider this a complication that would be better placed in a custom model for users that need this functionality?

[DavidMStraub]

... or perhaps it's not straightforward as there is currently no way to define boundary conditions in 2D other than neg. tab/pos. tab/no tab?