Make an EBRAINS workflow for SpiNNaker

[rowleya]

Make a workflow for EBRAINS demonstration, something like the following:

• Extract a model from the EBRAINS Knowledge Graph (might need to specify an exact python file within the model, or else require that an exact python file is specified within the Knowledge Graph). The Cortical microcircuit may be a good example to start with.
• Run the model on SpiNNaker. This could be in EBRAINS Jupyter, or using the NMPI service. EBRAINS Jupyter is possibly preferable, but is currently slow (see SpiNNakerManchester/SpiNNMan#1162)
• Run the model on NEST using HPC.
• Evaluate the results using HPC.

There is apparently a BrainScaleS example that does the HPC parts. Currently this doesn't do the Knowledge Graph part though.