use network name uploaded by user as object name

[ebey]

Functions within the shiny code that take in a network object use the nw() reactive object, which is convenient, except for a few scenarios when a different behavior would be more helpful for the user.

• When fitting a model, edgecov and dyadcov terms require nw() argument instead of actual network name
• The printed model summary shows nw() ~ edges

This is probably a long term issue.