I've written a `SchemadParDo(input_field: str, output_field, dofn:DoFn)` transform for more easily writing a Schemad transform given a DoFn.
Is this something worth upstreaming into the Beam Python SDK? I wrote it to make it easier to convert our current set of dofn's into schemad dofns for use with the YAML SDK. Just wanted to gauge interest before setting up the dev env again
