Add some linting checks to CSVs

[manics]

Add CSV checks from https://github.com/IDR/idr-utils/blob/e1050be194a9bf3c4ac7829d5993f20e3c9295ba/scripts/travis-check.py to the metadata plugin.

[sbesson]

https://github.com/IDR/idr-utils/blob/master/scripts/annotate/check_annotations.py also includes a few minimal checks (like row duplication)