http2: fix issues with aborted `respondWithFile()`s

PR-URL: https://github.com/nodejs/node/pull/21561
Fixes: https://github.com/nodejs/node/issues/20824
Fixes: https://github.com/nodejs/node/issues/21560


Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Ujjwal Sharma <usharma1998@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>