Format the generated source with CSharpier

[TwentyFourMinutes]

This would allow for way easier debugging of the generated sources. However, this feature should be opt-in as CSharpier takes time to do its magic and we do not necessarily want to format it for every build. An attribute on the assembly such as [FormatVenflowSource] would be a way to accomplish that. Anyhow we will need to wait until there is a proper way to pass the sources to CSharpier.