unapi: avoid deleted call numbers, copies, and sunits

unapi: avoid deleted call numbers, copies, and sunits

The rewrite of unapi removed the filters for deleted call numbers that
were added to master in LP# 893315 / commit hash 47a16f516d. Without
this filter, it is possible to return pages of results that would show
nothing in the TPAC because all of the call numbers were deleted.

This commit reinstates the check for the deleted condition on call
numbers and adds a check for the deleted condition on copies and serial
units as well.

The check could be made conditional by adding yet another parameter to
the unapi api, but there appears to be no compelling reason to make the
signature more complex for now.

Signed-off-by: Dan Scott <dscott@laurentian.ca>