SSP-1790 Load all terms into client-side store

Fixes an issue where MAP would effectively display a random term
if you had more terms in the db than fit into the first client-side
result page.

This is effectively a cherry-pick of
5cc82c2e411ef0c5f1a83ccff1906f5fcfefa712 but an actual cherry pick
was impossible because whitespace pages made the patch *far* too
broad.