Base-worker cache system upgrade

Refs https://gitlab.com/teklia/workers/ufcn/-/issues/42

Refs https://gitlab.com/teklia/workers/base-worker/-/issues/167

A new field was introduced in the base-worker cache on the CachedElement model. This means that the elements table created during initialization must be updated as well.

A new release of the base-worker system will soon be available so that using an incompatible cache version will fail nicely.