Dynamic configuration & creation of multiple plots of the same type

Currently, we have a predefined list of plot types and for each plot type we display exactly one plot.

The plot is configured in a configuration tab once before the model is simulated.

Idea is to move towards a more dynamic way of configuring and plotting data.

Netpyne-UI should allow users to

* Configure more than one plot per type (e.g. three different raster plots of different cells and time resolution)
* Configure & create **after** simulation completed, this allows to explore the underlying data

Start by mapping the existing configuration tab, predefined plot-type list, and plotting entry points in NetPyNE-UI. Review how simulation data becomes plots and how plot settings are stored. Done should include multiple plots of one type and plot configuration and creation after simulation completes, with corresponding tests or documented verification.

Written by the indexing model from the issue text.