Parse attribute column of a GTF file and create correct qualifiers

Currently the 9th attribute column of a GTF is parsed into qualifiers of the corresponding annotations, however, all qualifiers are called "attr". See the attached screenshot.

For example, for the following line:

chr20	ensembl_havana	gene	87250	97094	.	+	.	gene_id "ENSG00000178591"; gene_version "6"; gene_name "DEFB125"; gene_source "ensembl_havana"; gene_biotype "protein_coding";

a "gene" annotation should be created with the following qualifiers:

• gene_id (with value "ENSG00000178591" without quote marks).
• gene_version
• gene_source
• etc.

As sample data use, for example, files "Homo_sapiens.GRCh38.dna.chromosome.20.fa.gz" (a sequence) and "chr20_ref.gtf" (the corresponding GTF file), located in the ".../test/UGENE-6398" folder on the file server.