Less strict declarative style Endpoint implementation

[pocorall]

When I tried migrate my imperative style Route implementations to declarative style, I was frustrated by:

1. cannot access Request object
2. cannot return Response object
3. exceptions must be handled using codec, it isn't falls through and catched with Routes.handleErrorCause later.

I know that this is intentional design decision. Accessing directly to Request and Response is discouraged. However, access to these objects is necessary at least for migration purpose.

As a motivating toy example, refer to this code:

object EndpointExample extends ZIOAppDefault:
  class NoProblemException(message: String) extends Exception(message)

  private val myEndpoint1 =
    Endpoint(Method.GET / "my-endpoint1").query(HttpCodec.query[Option[String]]("id"))
	  .query(HttpCodec.query[String]("name")).out[String]

  private def myRoutes = Routes(
    myEndpoint1.looseImplement { (maybeId: Option[String], name: String, req: Request) => // I hope this work
      ZIO.fail(new NoProblemException(s"my-endpoint1 $maybeId $name, requested from ${req.remoteAddress}"))
	  // alternatively, the code below should also work
	  // ZIO.succeed(Response.text("OK with Response object"))
  })

  def errorProcessor(cause: Cause[Any]): Response =
    cause.failureOrCause match
      case Left(failure) => failure match
        case i: NoProblemException => Response.json(s"""{"message": "${i.getMessage}"}""")
        case i: Throwable => Response.text("My custom response")
      case Right(cause) => Response.fromCause(cause)

  def run: ZIO[Any, Throwable, Any] =
    Server.serve(myRoutes.handleErrorCause(errorProcessor)).provide(Server.default)

I hope a new method Endpoint.looseImplement would provide this generous access to Request, Response, and ZIO.fail handling from Routes.handleErrorCause.