feat:Combine AsyncToJson and TextractGenericAsyncSfnTask

On the other hand, I am thinking why not put AsyncToJson as an inherent function of TextractGenericSyncSfnTask instead of a separate Task? This way we always get consistent output. If we don’t want to delete the original JSONs, we can provide a prop retain_orig_resopnse= true/false which will allow developers to either retain or get rid of the original JSONs. IMO, we should probably implement the latter (so the output manifest in the previous point will have output_path as this consolidated JSON always, plus the original output path if the retain_orig_resopnse prop is set to true). This applies for AnalyzeDoc & AnalyzeExpense Async except that there’s no post processing required for Expense since the JSON is always combined by Textract by default (afaik).