Handle non-energy scans that are saturated/underexposed

[pbeaucage]

@delongchamp's saturation detection routine assumes the scan is an energy series, which breaks if you take a spiral/spatial scan. This adds a try/except to handle non-energy scans, not particularly gracefully but good-enough.

• Added a try-except block to handle potential exceptions when accessing md["energy"][idx] and provide a fallback message indicating affected frames if an exception occurs. [1] [2]