The old approach required adding a special virtual field
to any table potentially needing such foreign-id pagination and
also still required manually sorting according to pagiantion settings
since the pagination helper does not know whether
this virtual field was set or not.
Using lists with each entry containing the pagination id and the actual
entry insterad allows any table to use this mechanism unchanged and
does not require manually sorting.
Since it was unused, this also drops the pagination mode paramter from
fetch_favourited_with_fav_id.
Furthermore, as a side effect of this change a bug in the favourite
benchmark is fixed. It used to incorrectly attempt to use IDs of
the liked objects for pagination instead of the like IDs as advertised
in Link headers.