Additional bulk adjunct query operations

[JackLewis-digirati]

What does this change?

Resolves #1160

This PR adds a pair of new endpoints to allow further querying of data, along with enabling querying. These mimic existing functionality in assets

• GET /customers/{customer}/adjunctQueue/batches/{batchId}/current
  • Adjuncts that are currently part of the batch (i.e.: not superseded)
• GET /customers/{customer}/adjunctQueue/batches/{batchId}/adjuncts
  • Adjuncts that were part of the batch when first created (i.e.: this would include adjuncts that nave been superseded)

[JackLewis-digirati]

Summary

Implements #1160: two new GET endpoints for listing the Adjunct members of an adjunct batch, mirroring the existing asset/image batch-queue endpoints (/queue/batches/{batchId}/images and /assets).

• GET /customers/{customer}/adjunctQueue/batches/{batchId}/current — adjuncts whose Batch currently points at this batch.
• GET /customers/{customer}/adjunctQueue/batches/{batchId}/adjuncts — adjuncts that were part of the batch at creation time (via the AdjunctBatchAdjuncts join table), even if since reassigned to another batch, excluding any since deleted.

Both support page/pageSize paging (same ApiSettings.PageSize config as the asset endpoints) and orderBy/orderByDescending, with Created as the only supported sort field per the ticket.

Notable implementation details

• Reuses the existing generic paging plumbing (PagingHelpers.CreatePagedResult, HydraController.HandlePagedFetch/SetPaging/SetOrderBy) unchanged.
• Introduces a shared GetBatchEntitiesBase<TEntity, TRequest> in API/Infrastructure/Page, extracting the "run paged query → if empty, check the batch exists to disambiguate 404 vs empty page" pattern that was previously duplicated between the asset (GetBatchAssetsBase) and new adjunct (GetBatchAdjunctsBase) handlers. Both now just supply their entity-specific filter/ordering/batch-existence hooks.
• The historical /adjuncts query joins AdjunctBatchAdjuncts to Adjuncts on the composite (AdjunctId, AssetId)/(Id, AssetId) key, since there's no Adjunct navigation property on the join entity.
• 10 new integration tests cover 404s, paging, Created ordering, and the two edge cases that most matter for this ticket: an adjunct reassigned to a different batch drops out of the old batch's current listing but stays in its adjuncts (historical) listing, and a deleted adjunct drops out of adjuncts entirely.

No database migration required — this only adds read endpoints over existing tables.