samplenames() to return sample names in order of appearance in genodata

[pdimens]

description
currently, samplenames() returns a list of samples in the metadata dataframe, which is not always consistent with the appearance in the genodata. This behavior (for under-the-hood accuracy) needs to be consistent. The genodata df needs to always be sorted by [:name, :locus] and samplenames should return unique(genodata.name). It would probably be best for metadata.sampleinfo to list samplenames in parity with this.