TPAC: Show preferred library copies only in consortial scope

TPAC: Show preferred library copies only in consortial scope

A refinement of the preferred library display: only when the user is at
the consortial scope should the preferred library copies float to the
top. At all other scopes, the preferred library copies will appear in
their proper place in the org unit hierarchy (or not at all if outside
of the chosen scope).

Signed-off-by: Dan Scott <dan@coffeecode.net>