Plan for VS2022

[mrlacey]

This might be a lot of work.

It would be really good to update the roslyn dependences before doing this.

Consider re-combining into a single package to help manage multiple project references and shared code.
The original move to multiple packages was based on feedback that people would like fine-grained control over what they install. Telemetry indicates that very few people are only installing some packages. As long as the ability to disable/enable functionality exists, I don't think combining into a single package will be an issue, especially if this enables VS2022 support and allows for faster releases in future.

[mrlacey]

X-Ref #481