ML Notebooks should use Plotly.NET

[beccamc]

Replace XPlot with Plotly.NET.

Blocked on..

• Plotly.NET getting signed. Strongly named assembly plotly/Plotly.NET#175
• Also waiting on C# improvements Rewrite C# Compatibility Layer as bindings in C# plotly/Plotly.NET#285

[kMutagene]

Both should be resolved: The newest releases have strong names and basic native C# bindings are available as well (plotly/Plotly.NET#294, https://www.nuget.org/packages/Plotly.NET.CSharp/).

[JakeRadMSFT]

@kMutagene thoughts on the interactive package depending on the CSharp package?

[kMutagene]

@JakeRadMSFT what would be the benefit of that other than only referencing one package in C# notebooks. Ideally I would like to keep these packages separated, as that would also mean that an F# notebook using the interactive package would install an unused dependency.

[JakeRadMSFT]

Resolved with: #49