Add -NoProject switch

[markdnelson]

Is your feature request related to a problem? Please describe.

A significant amount of time is spent adding each generated file to a project. If the project variable is null, adding the file is skipped, and code generation is significantly faster.

Describe the solution you'd like

Add a command line switch to the cli to skip project generation/adding the file to the project.

Describe alternatives you've considered

Improve the performance of adding each file to the project.

Additional context

C# projects no longer need to reference every file they contain, instead you can exclude files you don't want. This means that the presence of the file is enough to include it in your project.