Presentation 2 "related" property not upgraded correctly.

[stephenwf]

From:
https://github.com/tify-iiif-viewer/tify/blob/main/src/plugins/store.js#L17-L45

There are some improvements to the IIIF v2 to v3 conversion that still need addressed. The "provider" label is now empty in v2.2.0 but the "related" property is not being handled correctly.

cc @t11r