We should add a Add linker-friendly Roslyn source gen version of [RequestDelegateFactory](https://github.com/dotnet/aspnetcore/blob/8cf98856bb96c7aad8373ae5b1fa6e7f021f649e/src/Http/Http.Extensions/src/RequestDelegateFactory.cs) similar to what's [in uController](https://github.com/davidfowl/uController/blob/aa8bcb4b30764e42bd72d326cb2718a4d4eaf4a9/src/uController.SourceGenerator/uControllerGenerator.cs)
We should add a Add linker-friendly Roslyn source gen version of RequestDelegateFactory similar to what's in uController