LP#2051708: Cache MR summary calculations

LP#2051708: Cache MR summary calculations

As part of the angularization of the staff catalog, new logic was
added to the bib summary API that gathers record attributes for the
constituent records of a result's metarecord. For very large
metarecords (~100+ constituents) this can be very slow, and when a
search returns many bibs from the same metarecord, the underlying
data is retrieved separately for each bib.

This commit creates a temporary local cache to avoid repeating the
caclulation of MR summary data on the same result set page.

Release-note: Improve speed of searching for and displaying (in Staff View) titles that are members of large metarecord sets.

Signed-off-by: Mike Rylander <mrylander@gmail.com>
Signed-off-by: Galen Charlton <gmc@equinoxOLI.org>
Signed-off-by: Jason Boyer <JBoyer@equinoxOLI.org>