Bug 24289: Add foreign keys on *_holidays.branchcode tables

Bug 24289: Add foreign keys on *_holidays.branchcode tables

Those are missing foreign keys, it will also clean the holidays tables
and automatically remove the holidays when a library is removed.

Test plan:
0. Do not apply this patch
1. Create a new library
2. Create special and repeatable holiday for this library
3. Remove the library
=> Notice that the holidays still exist in DB
4. Apply this patch
5. Execute the update database entry
=> Notice that the holidays for this library have been removed from the DB
6. Repeat 1-3
=> Notice that the holidays have been removed along with the library

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>