Add a generic extension hook to PageAggregate::findPageIDs().
Add a generic extension hook to PageAggregate::findPageIDs().

redema/silverstripe-patchwork,edlund/silverstripe-patchwork,redema/silverstripe-patchwork,redema/silverstripe-patchwork,edlund/silverstripe-patchwork,edlund/silverstripe-patchwork