Bug 29212: (follow-up) Add futuredate attribute to date picker

Bug 29212: (follow-up) Add futuredate attribute to date picker

This patch adds the "futuredate" attribute to the "Hold not needed
after" date field in the OPAC hold process.

To test, apply the patch and log into the OPAC.

- Locate a bibliographic record and being the process of placing a hold.
- Click "Show more options" to display the date fields.
- If the OPACAllowHoldDateInFuture system preferences is enabled:
  - Set "Hold starts on date" to a date in the future.
  - Trigger the date-picker in the "Hold not needed after" field: You
    should be limited to dates *after* the date you selected above.
- If OPACAllowHoldDateInFuture is disabled:
  - The "Hold starts on date" will no longer be present.
  - Trigger the date-picker in the "Hold not needed after" field: You
    should be limited to dates after today.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>