Parse gene and transcript version from GFF/GTF file

[nakib103]

https://www.ebi.ac.uk/panda/jira/browse/ENSWBSITES-2775

Transcript version is always 1 when GFF file is used. It seems it has been hard coded. This PR fixes this issue -

• try to read version from GFF/GTF file
• if there is no version in the file reports no version even if --transcript_version is given.

Test

Test with rs699 and see if it matches transcript and gene version -

vep --id "1 230710048 rs699 A G" --force --gff /pathto/genes.gff3.bgz --fasta /pathto/Homo_sapiens.GRCh38.dna.toplevel.fa.gz --transcript_version --gene_version

Check the ticket for GFF and FASTA file location for testing.