Remove RefSeq ID / version from transcript consequences

[nawatts]

Currently, transcript annotations may be annotated with refseq_id / refseq_version fields.

https://github.com/broadinstitute/gnomad-browser/blob/b4e38686e23fe4a31ff7c9541fe78b82b4df286b/data-pipeline/src/data_pipeline/data_types/variant/transcript_consequence/annotate_transcript_consequences.py#L84-L120

The original intent here was to show both Ensembl and RefSeq IDs for MANE Select transcripts. However, most transcript annotations would not be from MANE Select transcripts and thus would be missing values for these fields (and the corresponding Ensembl ID/version fields if they were added). Once all RefSeq annotations are shown on the variant page, these fields wouldn't be particularly useful, so remove them.