LP#1710747: Absolute URL for Open Graph image property

LP#1710747: Absolute URL for Open Graph image property

The Open Graph image property requires the full absolute URL rather than the
relative URL that was previously used on the record summary page.

Test Plan:
Pre-patch - Visit a record summary page in the catalog. View the source of the
page. In the head section, find the og:image meta property. The content will
display a relative URL to the record's book jacket cover image.

Post-patch - When viewing the source of the page, og:image will display the
full URL.

Signed-off-by: Kathy Lussier <klussier@masslnc.org>