Returns a list of request IDs in the same order as specs. The backend
now fails-fast on the first un-enqueable spec — the call rejects with
the underlying AppError. Callers should surface the rejection via
surfaceUnknownError (see Toolbar.handleUpload).
Bulk-enqueue multiple uploads.
Returns a list of request IDs in the same order as
specs. The backend now fails-fast on the first un-enqueable spec — the call rejects with the underlyingAppError. Callers should surface the rejection viasurfaceUnknownError(seeToolbar.handleUpload).