Switch from deprecated qualifiers field to qualifier field and include closure expansion

[kevinschaper]

While working on adding sssom to solr, I noticed some oddities around whether the qualifiers field was getting an expansion, and I remembered that RENCI folks had noted that qualifiers in our graph is deprecated.

Initially I was going to try to squeeze that update into the other PR, but I found that the biolink model actually needed an update to include qualifier as an Association slot. I made a PR for that, and once it's in, we can update the ingests & schema.

[kevinschaper]

The biolink model release that we needed for this is out now, but I hate to have the Solr schema change so late in the release process, so I want to push this change to the start of the new release.

[kevinschaper]

While changing the ingests from qualifiers to qualifier I ran into qualifier being a single valued field. Alliance (not sure which taxa, but not all of them) and PomBase g2p both have the potential for using multiple qualifiers on g2p associations.

Since the deprecated field isn't haring us right now, I'm going to move this a couple releases ahead.

[kevinschaper]

Removing milestone, since it's blocked by biolink model