Bring back GTF attributes parser?

[nvictus]

Options:

• parse_gtf_attributes as read_gtf() with an option to parse
• wrap an existing external tool for gtf parsing and return a pandas dataframe
• keep it as a separate operation to apply to any key-value like column.

[gfudenberg]

any thoughts on which option would be best cc @nvictus @agalitsyna ? It seemed like there was quite the extensive discussion in #123.

@smitkadvani was interested in implementing whichever solution made the most sense as it might clean up some code in one of his ongoing projects

[gamazeps]

for what it's worth I have not had any issues with gtfparse on neither GENCODE or ENSEMBL.

So we could just have a wrapper around gtfparse.read_gtf, and rename the'seqname' to 'chrom' to have a valid bedframe ?