Last week, @rdicosmo asked me if we could get more details regarding the execution
of a loading task associated to a 'Save code now' request.

As the 'Save code now' feature starts to get more and more advertised in the
scientific community, we need to ensure it is reliable (especially for the
saving of git origins). So, we should be able to quickly get relevant task
execution details in order to analyze issues for those who failed.

So, in order to provide some feedback to users regarding the loading task execution
associated to a save code now request, add a dedicated function in related module.

This function will notably try to extract relevant task execution info (log message,
worker name, ...) by querying the elasticsearch cluster of Software Heritage.

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