[2.0] Support API Versioning

[Tiberriver256]

There is another project focused on providing versioned OData APIs for different versions of .NET Web API across .NET and .NET Core here:
https://github.com/microsoft/aspnet-api-versioning

I had opened an issue quite awhile ago on their repo to ask if it was compatible with RESTier:
dotnet/aspnet-api-versioning#404

They had suggested it might be required to make some modifications in the RESTier code to support but weren't 100% sure. I had forgotten about this for awhile but we're getting to the stage in our API development life-cycle that we're going to start needing versioning. Was this on the roadmap at all for RESTier?

[robertmclaws]

Likely API versioning options for 2.0:

• https://github.com/dotnet/aspnet-api-versioning
• YARP reverse-proxies

Will need code and documentation for both options.