http2: fix end without read

Adjust http2 behaviour to allow ending a stream even after some
data comes in (when the user has no intention of reading that
data). Also correctly end a stream when trailers are present.

Backport-PR-URL: https://github.com/nodejs/node/pull/22850
PR-URL: https://github.com/nodejs/node/pull/20621
Fixes: https://github.com/nodejs/node/issues/20060


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>