Consider switching canonical data sheets to SSSOM TSV format

[cthoyt]

There are a few benefits:

1. The SSSOM format uses CURIEs exclusively, so there won't be any confusion about identifier style ambiguity
2. We can use SSSOM tooling instead of implementing it ourselves or alternatively contribute our tooling back to the SSSOM community
3. There would be fewer artifacts that need to get built, and the messaging in Biomappings could be a bit more straightforwards

A few drawbacks:

1. Requires more programming churn
2. Have to assess how downstream dependencies consume Biomappings

Note: we're still allowed to choose our own prefix map with our SSSOM files, so we don't necessarily have to consider conflicts in nomenclature with the OBO community, but it would probably be a good idea to consider.