Bug 16469 - Remove the use of "onclick" from some catalog pages

Bug 16469 - Remove the use of "onclick" from some catalog pages

This patch removes the use of "onclick" attributes from two
catalog-related templates: The local cover image viewer and the search
results page. Events are now defined in JavaScript.

To test:

On the search results page:

- Perform a catalog search which will return multiple results.
- On the search results page, confirm that the "Select all" and "Clear
  all" links at the top of the results table work correctly.

In the local cover image viewer:

- The LocalCoverImages and AllowMultipleCovers system preferences must
  enabled, and at least one catalog record must have at least two local
  cover images attached.
- Locate that record in the catalog and view the detail page for it.
- Click the cover image in the "Images" tab to go to the image viewer
  page.
- Clicking each local cover image thumnail should correctly display the
  larger version of each image.

Signed-off-by: Nikos Chatzakis, Afrodite Malliari <nchatzakis@datascouting.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>