Improve tracing related to WorkManager

On async processing the tracing context is passed by the stream service inside record,
but the legacy work manager is also passing the context inside Work, as a result we see double activity:

parent -> computation record
parent -> work

instead of a scoped activity:
parent -> computation record -> Work

Also, the name of the span work could include the category so we have work/ListerWork/updateThumbnail instead of just work/ListenerWork which is hard to read.

In addition, It will be nice to trace ShellExecutor in a span to have an idea of all invoked transformations.