Adding possibiliy to visualize the process graph

[bgoesswe]

In the hackathon the idea came up to enable the users to visualize the process graph in a nice, like an actual image of an graph.
Some tools were also mentioned to use it e.g. Tensor Board
There is already a python package with a similiar solution in the Dask package

[jdries]

This exists now:
to_graphviz

[soxofaan]

example:

Note however that this requires the installation of an additional package graphviz (https://pypi.org/project/graphviz/).
It is currently not listed as a dependency of the openeo client, because it is not vital and it is probably a hassle to get working on windows.