The ReadRepository::contains method can be wasteful since it opens and ODB handle and immediately closes it, while its usage may reuqire checking multiple OIDs in a batch, e.g. in the RefsStatus calculation.

Instead, introduce a ReadOdb trait, an Odb associated type to ReadRepository, and a new method ReadRepository::odb for getting the ReadOdb type.

The use of contains in RefsStatus uses the ReadOdb instead to improve the usage performance.

ReadRepository::contains remains a part of the trait as a follow-up task.

Changes:

• Move getting the Odb handle outside the loop for each insert.

Changes:

• Update commit message title