Some low-hanging import fixes

This commit is primarily converting Request and Response types within
the transport module to Axum 0.7 Request/Response. There is still more
to come to finish this conversion.

There are also small changes such as updating the hyper service builder
syntax.

Over the course of this commit,it was discovered that hyper-util is missing
`http2_max_pending_accept_reset_streams`.

Replaced with `tokio::net::TcpStream`.
Inspired by hyperium/hyper#2850

- use `Frame`.
- update `poll_data` to `poll_frame`
- remove `poll_trailers` in most places

I am not sure that a simple rename of `poll_data` to `poll_frame` is
right. I also left one instance of `poll_trailers` in
*tonic/src/codec/decode.rs*.

`is_connect` was deprecated when the higher-level client was removed
from hyper.
The corresponding comments are removed as well.

`http::Extensions::insert` requires `T: Clone` so we add it.