Log application_Version in App Insights

[brettsam]

From MicrosoftDocs/azure-docs#9030

If someone is using an application version in their precompiled assemblies, we may be able to apply that to their App Insights logging in the application_Version field. It's somewhat possible to do this manually today with structured logging, but that only applies to user logs.

Options for non-precompiled assemblies could be to generate a hash on startup based on files -- we've prototyped this in the past but never went any further.