Bug 22276: Add client storage of user-selected DataTables configuration

Bug 22276: Add client storage of user-selected DataTables configuration

This patch enables use of DataTables' built-in session storage of table
configurations. DataTables by default uses the browser's localstorage
feature to store the state of each DataTable, including which columns
have been hidden by the user.

Our table settings system has always overridden this saved state. This
patch adds a check for a saved configuration state and if present loads
the saved state instead of the default state.

The system is enabled in this patch on the libraries administration
page. To test, apply the patch and open go to Administration ->
Libraries.

- Use the "Columns" button to change the visibility setting of multiple
  columns.
- Navigate away from the page and then back to test that the visibility
  settings have been kept.
- Go to Administration -> Table settings -> Administration and change
  the visibility settings for the "libraries" table in a way that it
  differs from the visibility settings you set manually.
- Return to the libraries administration page and confirm that your
  manual settings are still being loaded instead of the defaults from
  table settings.

Signed-off-by: Solène Desvaux <solene.desvaux@biblibre.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>