Bug 19751: Holds awaiting pickup report should not be fixed-width

Bug 19751: Holds awaiting pickup report should not be fixed-width

This patch changes the grid used for the holds awaiting pickup report so
that the results are full page and fluid instead of fixed-width.

To test, apply this patch and the patch for Bug 19700 if necessary.

View the holds awaiting pickup report. The report should fluidly fill
the page width.

Test with the CircSidebar system preference enabled and disabled.

Signed-off-by: George Williams <george@nekls.org>
Signed-off-by: BWS Sandboxes <ByWaterSandboxes@gmail.com>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>