Visualize networks and cells via view

[michaeldeistler]

A new visualizer for jaxley.

I am currently using networkx only for plotting the "point neuron view": net.vis(detail="point"). For all other things, I wrote my own plotting function. I think that what is implemented now is very flexible and did not require much code.

New API

net.vis()
net.cell([0, 1, 3]).vis()
net.cell(0).branch([0, 2, 3]).vis()

also works for groups:

net.cell(0).add_to_group("excitatory")
net.cell(3).add_to_group("excitatory")
net.excitatory.vis()

Thanks to this new API, I will remove the highlight_branch_inds option and rely on overplotting instead.