Bug 33848: Enabling Coce in the OPAC breaks cover images on bibliographic detail...

Bug 33848: Enabling Coce in the OPAC breaks cover images on bibliographic detail page

Bug 32412 added an additional "context" parameter to KOHA.coce.getURL.
The code which pulls a Coce image for the "main" cover image slider
needs to include the correct context parameter for the images to load.

This patch also makes a minor correction to CSS in order to make the
cover image slider "dots" change color to highlight the current slide.

To test, apply the patch and rebuild the OPAC CSS.

- Enable multiple cover image sources in the OPAC including Coce, e.g.
  Amazon, Google, OpenLibrary, etc.
- Search for a title which will match multiple cover image sources. In
  the sample data a search for "Perl" will return good results.
- Note the number of cover images loading for a title in the search
  results.
- View the detail page for that title. There should be the same number
  of covers in the cover image slider.
- Clicking the slider navigation dots should work to show each image,
  and the dot should change color to highlight the current image.

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>