Certain APIs consuming HTTPTasks want to know if the response has
finished. However, in cases such as protocol errors the h2 RecvStream
will return `is_end_stream` which may be associated with an HTTPTask
that was not actually the end of stream. This affects systems such as
caching which wants to know when the response has properly finished for
finishing a cache miss.

This change attempts to check if the stream has ended due to an h2 error
or not to forward a successful or Failed HTTPTask as appropriate.

The rust 2021 use rust version is 1.56.0, `matches` included in the
standard library prelude and thus is automatically in scope.

Includes-commit: ebc6cbf
Replicated-from: #414
Signed-off-by: Xiaobo Liu <[email protected]>

This change takes the existing API for ListenerEndpoint and modifies it to use a typical idiomatic builder style.

There are additional improvements which I feel can be made here, but I believe that it would be better to do them in subsequent commits in order to keep changes as incremental as possible.

In particular, I think that making socket options into sub-builder is probably a good move.

Currently the meta is attempted to be logged in a hit span that may or
may not exist (or has not started) depending on the cache phase.