Teach TPAC to show jacket images by Record ID

Teach TPAC to show jacket images by Record ID

Retrieve AC jackets by record ID in TPAC and include jacket image
even if we lack an ISBN/UPC.

Conditional output of the jacket image <img> tag breaks local added
content overrides by record ID. Make the inclusion of the jacket
image unconditional.

Use an onerror handler to hide broken jacket images for those cases
where we receive a 404 instead of a 1x1 placeholder.

Signed-off-by: Jeff Godin <jgodin@tadl.org>
Signed-off-by: Ben Shum <bshum@biblio.org>