Fix search filter pagination and number of search results displaying.

Review Request #10687 — Created Sept. 6, 2019 and updated — Latest diff uploaded

Review Board
reviewboard, students

When a filter (ie. "Review Requests" or "Users") is applied to a search,
any navigation in the pagination resulted in returning to "All Results".
This was because the active filter was not being referenced as a url
parameter when navigating the pagination links. There was also an issue
with several of the variables used throughout the template, including
the results count only displaying the number of results of the active
page, and the "last page" link referencing an empty url, causing it
to return to the first page.

The search functionality now passes the active filter to the url,
and the correct variables are being referenced for the last page link
and the number of search results.

This has been manually tested and I have verified that it is working
for all filters and pagination links.