Request: Side panel in EW should match layout's .85 max-width

https://github.com/adobe/da-nx/blob/fe5e95045e81b82f8f2e40c21522a11ea699c335/nx2/utils/panel.js#L4 sets the max width of the panel to .4 of the window innerWidth. This is quite small for the plugins we want to implement. Our use cases are a downstream app preview (consumes EDS content) and Target campaign management within the panel.

Ideally this would like work more like Layout view where I can freely drag the panel size to have up to more like a 85-15 panel split.

Start in nx2/utils/panel.js at the linked max-width calculation and inspect how the EW side panel is sized. Compare its behavior with the Layout view, then verify that the panel can expand to roughly an 85-15 split while preserving the existing panel behavior.

Written by the indexing model from the issue text.