These should be "contact", not "via", and there is no difference
between the N+ tap and the N+ source/drain, the P+ tap vs
the P+ source / drain (generally the contact cells are made to
include the active cut, needing no additional features to "just
work".
If you can't find them you can always just make a stack that
proper, and keep it local. I do this as a rule because GDS-II
stream out and in a couple of times tends to leave me with a
large number of identical-properties, distinct-name "contact"
cells in the GDS file (like, half of the cell count is 1x2 vias, the
minimum size used, after the first stream-out when using the
PDK "contact" menu to generate propertized via mosaics).