This moves the Content Libraries V2 backend from Blockstore [1] over to
Learning Core [2] For high-level overview and rationale of this move, see
the Blockstore DEPR [3]. There are several follow-up tasks [4], most notably
adding support for static assets in libraries.
BREAKING CHANGE: Existing V2 libraries, backed by Blockstore, will stop
working. They will continue to be listed in Studio, but their content
will be unavailable. They need to be deleted (via Django admin) or manually
migrated to Learning Core. We do not expect production sites to be in
this situation, as the feature has never left "experimental" status.
[1] https://github.com/openedx-unsupported/blockstore
[2] https://github.com/openedx/openedx-learning/
[3] https://github.com/openedx/public-engineering/issues/238
[4] https://github.com/openedx/edx-platform/issues/34283
