Save/restore state of NWB Explorer

[filippomc]

Saving and restoring the state of the application is a key feature for the scientist workspace.
The goal is to be able to save and reload whatever the user is visualizing in the current dashboard and the jupyter notebook for future use.

[filippomc]

@pgleeson what do you think to use this card to take care also of the notebook save/load

[pgleeson]

I see the saving/loading usage scenario as 3 stages:

1. a) save just the notebook contents and then b) manually reload the NWB file followed by recreate notebook from saved version (and probably rerun all cells)
2. a) save X=[pointer to NWB + notebook contents], then b) from X (which could be a single link or GH repo or zip file) recreate the filled NWBE + notebook
3. a) Save everything including state of gui elements b) reload everything in last state

I'd like to see 1 (or 2) in the short term, which would keep most users happy for a while, but this issue was probably aimed at scenarioo 3...