feat: Script for tabular clinvar submission

[bencap]

This pull request adds a script that exports variants from a given score set URN into a CSV/TSV with appropriate format to submit to ClinVar.

Run the script with

with_mavedb_db_session poetry run python3 -m mavedb.scripts.tabular_clinvar_submission <score set URN> ./output-directory --format csv

A few outstanding questions remain:

• For the Condition ID and Condition Value, we are generating MedGen and C0012634 (the generic 'disease' condition) for all score sets. We should verify this condition is appropriate.
• For Assay Type, we should talk with ClinVar about their various allowed assay types shown here: https://ftp.ncbi.nlm.nih.gov/pub/clinvar/functional_assay_types.txt. These assay types don't seem to have an appropriate ontology for certain assays in MaveDB, such as Label-Seq or VAMP-Seq.
• For Molecular Phenotype Measured, we should talk with ClinVar about an appropriate ontology for the field. We should also ensure we have a robust decision tree for moving from our controlled keywords for molecular phenotype to whatever we decide on with ClinVar.
• We should ensure that the score set method and primary publication are appropriate to send as the method and method citation.
• We should discuss how to handle score sets with categorical calibrations, as ClinVar's submission format only seems to accept range based calibrations.
• We should go through the other blank columns and verify these do not require submission values.