Backport changes from avro-js?

[valadaptive]

It seems like Apache's official avro-js package started out as a fork(?) of this project 9 years ago and has diverged since. It seems like there are a few open issues about supporting newer Avro features that may have already been implemented in avro-js. Might it be worth looking into the changes that avro-js has made and seeing how many of them can be backported to this repository?

[mtth]

SGTM. Specific feature requests and PRs very welcome. For any non-trivial changes, I'd just recommend discussing first (here or in a dedicated issue).