Org Mover: Implement selective sync scope for DesignManagement::Repository

Problem

We need to implement selective sync by organization: &17004. We can break up the work by data type.

Proposal

Implement the selective sync scope for the DesignManagement::Repository model.

Prerequisites

• design_management_repositories has a sharding key

If #514251 (closed) is not yet done, then implement a stub for GeoNode.selective_sync_by_organizations? which always returns false)

Acceptance criteria

When selective sync by organization is selected, then design repositories will be selectively synced on the secondary site, and selectively checksummed on the primary site.