gmt anno tv: add empty base class for versions

code-deduplication: mburnett, nnutter
move common properties to base class

code-deduplication: mburnett, nnutter
move common priorities methods to base class

code-deduplication: mburnett, nnutter
move more prioritization methods into base

code-deduplication: mburnett, nnutter
move _create_iterator_for_variant_intersection to base

code-deduplication: mburnett, nnutter
move is_valid_variant to base

code-deduplication: mburnett, nnutter
remove trailing whitespace

code-deduplication: mburnett, nnutter
move _prioritize_annotations to base

code-deduplication: mburnett, nnutter
move _highest_priority_error to base

code-deduplication: mburnett, nnutter
move _transcript_annotation_for_rna to base

code-deduplication: mburnett, nnutter
move _transcript_annotation_for_utr_exon to base

code-deduplication: mburnett, nnutter
move _transcript_annotation_for_flank to base

code-deduplication: mburnett, nnutter
move _transcript_annotation_for_intron to base

code-deduplication: mburnett, nnutter
move _apply_indel_and_translate to base

code-deduplication: mburnett, nnutter
move _coding_bases_after_position to base

code-deduplication: mburnett, nnutter
move _ucsc_conservation_score to base

code-deduplication: mburnett, nnutter
move _protein_domain to base

code-deduplication: mburnett, nnutter
move _determine_coding_position to base

code-deduplication: mburnett, nnutter
move _reduce to base

code-deduplication: mburnett, nnutter
refactor is_mitochondrial out of translate

and move translate to base

code-deduplication: mburnett, nnutter