[roll] Roll fuchsia [seriallistener][iomisc] Match strings split across multiple reads

It is possible for seriallistener to not match strings that are split
across multiple reads because each read creates a MatchingReader of its
own, thereby losing the matched pattern between reads. The fix replaces
MatchingReader and ReadUntilMatch* with Matcher for the reasons below.

ReadUntilMatch* functions are unsafe. Canceling their context doesn't
guarantee that an ongoing Read will be interrupted. Instead, it leaks
the goroutine wrapping the Read which is masked only by the fact that
the process is likely to exit soon after leaking the goroutine.

More importantly, io.Reader doesn't impose any concurrency requirements
on implementations. It is possible to invoke an unsafe operation on the
implementation of an io.Reader while its Read operation is blocked. In
particular, a retried Read may skip data.

Finally, MatchingReader in incorrect. It doesn't match patterns like
"AB" when read in steps of "A", "AB".

Matcher is simpler. It matches a single pattern and does so with an API
that allows multiple patterns to be matched in parallel. It returns a
boolean to confirm that its pattern matched instead of making the user
compare the returned string. Tests are more straightforward.

Original-Bug: 42085023
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1481137
Original-Revision: 9e9d22ec1007df48cf2339abe11385bc7580cc64
GitOrigin-RevId: 3e2555b6d247744ffef6fe21d58d8016fc13da29
Change-Id: I23de50a9680d1edc4c52042a36faaee115260418