Vasculature support

[matz-e]

@st4rl3ss summarized this on JIRA:

As preliminary work on this ticket I've had a conversation with Christos Kotsalos, that is interested as well in the vasculature support for brain-indexer.

Some of the main point of the conversation are listed below:

• the vascpy library could be used to load and manipulate vasculature datasets: https://github.com/BlueBrain/vascpy
• some basic examples on how vasculature datasets are loaded can be found in the following file: https://github.com/BlueBrain/AstroVascPy/blob/main/examples/compute_static_flow_pressure.py
• some more example on how to load and store vasculature data can be found here: https://github.com/BlueBrain/MultiscaleRun/blob/main/multiscale_run/bloodflow_manager.py
• It would be interesting to load both vasculature datasets with morphologies and query them together