Conventional.Roslyn vNext (#73)
* Initial work to update Roslyn conventions to dotnet 3.1
Solves the cross-platform issues with MSBuildWorkspace
Extracts Analyzers to a separate assembly to ensure they are decoupled from Microsoft.CodeAnalysis.Document, Microsoft.CodeAnalysis.Project, Microsoft.CodeAnalysis.Solution
* Conventions work in Rider both in IDE, and in tests.
Still TODO: Packaging the analyzers separately, pushing a new version of Best.Conventional.Roslyn, check the tools install / uninstall in VS 2019.
* Ensure Analyzers dependency is not a nuget-type dependency
We don't want to publish the analyzers seperately to the Roslyn project.
* Configures generated code analysis
* Adds category name to analyzers to ensure they display correctly in IDEs
