Synchronize JSON schema with odgi

[subwaystation]

pangenome/odgi#102 will bring in not one range of nucleotide positions per bin per path but an array of ranges per bin per path.

We need to update our parsing, internal representation and writing to JSON.

@dimatr Could you please take this over?

[subwaystation]

Example odgi bin output from pangenome/odgi#102
run1.B1phi1.i1.seqwish.gfa.og.w100.i99.json.gz