[Task] Implement batch list_versions across objects

[canelbirlik]

Description

List_versions are needed to resolve the latest version of the object and currently performed serially. E.g. during batch load, if an explicit version is not given, we serially resolve the latest version of the object.

1: Implement batched version resolution on backends(Threaded for remote backends)
1: Modify _load_batch to use the batched method.

Acceptance Criteria

• Implement integration tests to observe behaviour&latency improvement in batch cases

Priority

Medium (important but not urgent)

Estimated Effort (Story Points)

1 (0.5 day)