Barrel cortex workflow issues

[shimoura]

The barrel cortex is the first use case built entirely on entities, and with reoccurring subpopulations of the same cell type

• [ ] Can not easily define subpopulations (with labels) from placement
• [ ] Can not easily skip connectivity and rely on NEST connection rules with subpopulations
  • Missing connectivity set tags, combinatorial explosion
  • Can't identify node collections by label