Raise warning if GE metadata does not match expected values from product sequence

[tsalo]

Summary

At least in our GE test dataset, the metadata does not match the GE product sequence, even though that dataset did use the product sequence. This has resulted in CBF values that don't make sense.

Additional details

LabelingEfficiency = 0.6 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2914847/)
M0scale = 96 (32 x 3, which is the typical number of M0 scans)
BackgroundSuppression = True
BackgroundSuppressionNumberPulses = 3