Bug 33914: Improve translation of title tags: Course reserves

Bug 33914: Improve translation of title tags: Course reserves

This patch updates course reserves templates so that title
tags can be more easily translated.

To test you should have the UseCourseReserves system preference enabled.
Apply the patch and confirm that the following course reserves
pages have the correct title tags:

- Course reserves
- New course
- Course details
- Edit course
- Add reserves (step 1 and 2)
- Batch add reserves (step 1 and 2)
- Batch remove reserves
- Invalid course (/cgi-bin/koha/course_reserves/course-details.pl?course_id=)

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>