Report Failed Lazy Rendition Builder Work Blob Computation to client

AbstractLazyCachableRenditionProvider should report to the client an error response code when the async Rendition Builder Work Blob Computation it launches on behalf of the client fails.

Specifically, when a Work error occurs, method AbstractLazyCachableRenditionProvider.render(doc, def) never sees condition TransientStore.isCompleted(key) == true As a result, a Work failure causes the client to continually receive "inprogress" responses giving it no indication of failure.