[viz]: manage modal proof of concept, fixed a few bugs
[viz]: manage modal proof of concept, fixed a few bugs

neurodata/ndstore,openconnectome/open-connectome,openconnectome/open-connectome,neurodata/ndstore,openconnectome/open-connectome,neurodata/ndstore,neurodata/ndstore,openconnectome/open-connectome,openconnectome/open-connectome,openconnectome/open-connectome