Setup graph for SPH

After being way to annoyed with the overwhelming diversity of SPH setup a solution had to be found to tackle it !

This solution is the generalized setups in a form of a graph where link pass PatchData from a to node to another one.

Node types

Node can be generators (e.g. lattice hcp, monte carlo, ...) modifiers (strechmapping, disc warp, ...) or combiners (Just combining the result of two other nodes).

Exemple

Imagine a even number generator, a modifier (multiplier) that multiplies the result by 10, and a combiner.

The following should generate the list of even numbers multiplied by 10, twice.

Python wish

We want something that look like this to generate the graph above

When the wish come true

Well the answer is this PR.

It implements currently a way to generate a node and apply the resulting setup, but also: - LatticeHCPGenerator

With the current PR the sedov taylor setup for SPH is now

setup = model.get_setup()
gen = setup.make_generator_lattice_hcp(dr, bmin,bmax)
setup.apply_setup(gen)

Or for the sod tube:

setup = model.get_setup()
gen1 = setup.make_generator_lattice_hcp(dr, (-xs,-ys/2,-zs/2),(0,ys/2,zs/2))
gen2 = setup.make_generator_lattice_hcp(dr*fact, (0,-ys/2,-zs/2),(xs,ys/2,zs/2))
comb = setup.make_combiner_add(gen1,gen2)
setup.apply_setup(comb)