6.0.0 Preview 2

This is a quick iteration to Preview 2 with a few key fixes and enhancements.

Enhancements

All Platforms

• Added ApiExplorerOptions.RouteConstraintName (useful for resolving API parameters by constraint)

ASP.NET Core

• Added DescribeApiVersions extension method which can be used by WebApplication
  • This is functionally equivalent to IApiVersionDescriptionProvider
  • The implementation uses the DefaultApiVersionDescriptionProvider
• DefaultApiVersionDescriptionProvider now uses EndpointDataSource instead of IActionDescriptorCollectionProvider
• ApiVersionMetadata.Name will be used for controller token in ActionDescriptor for Minimal APIs, if specified
  • For Minimal APIs, this is typically provided via app.DefineApi(name: "My API")
• Added feature parity with OpenApiRouteHandlerExtensions such as Accepts, Produces, etc
  • Note: This might change in the future. See dotnet/aspnetcore#39604
• Added OpenAPI example with API Versioning, Minimal APIs, and Swashbuckle

Fixes

ASP.NET Core

• Support API Explorer extensions for Minimal APIs (#812)