Enable HTTP/3 for HttpSys (and IIS?) #29077 (#35316)

...ervers/HttpSys/src/RequestProcessing/RequestContextOfT.cs

...s/HttpSys/test/FunctionalTests/Http3SupportedAttribute.cs

src/Servers/HttpSys/test/FunctionalTests/Http3Tests.cs

...icrosoft.AspNetCore.Server.HttpSys.FunctionalTests.csproj

...Kestrel/Transport.Quic/test/QuicConnectionContextTests.cs

...estrel/Transport.Quic/test/QuicConnectionListenerTests.cs

...ers/Kestrel/Transport.Quic/test/QuicStreamContextTests.cs

.../Kestrel/Transport.Quic/test/QuicTransportFactoryTests.cs

src/Servers/Kestrel/Transport.Quic/test/WebHostTests.cs

...red/test/TransportTestHelpers/MsQuicSupportedAttribute.cs

...l/test/Interop.FunctionalTests/Http3/Http3RequestTests.cs

...strel/test/Interop.FunctionalTests/Http3/Http3TlsTests.cs

src/Shared/HttpSys/NativeInterop/HttpApiTypes.cs

src/Shared/HttpSys/RequestProcessing/NativeRequestContext.cs