Bug 36074: Add classes to materials specfied message on check in and checkout when...

Bug 36074: Add classes to materials specfied message on check in and checkout when CircConfirmItemParts is on.

To test:
1. APPLY PATCH
2. Set CircConfirmItemParts to 'Require'.
3. Add a materials specified message to an item. ( 952$3 )
4. Add the following CSS to your IntranetUserCSS:

    .mats_spec_label { color: white; background: purple;  }
    .mats_spec_message { color: white; background: green; }

5. Checkout that item. Notice the message should be green and the label (Note about the accompanying materials:) should be purple.
6. Check in that item. Notice the message should be green and the label (Note about the accompanying materials:) should be purple.

Signed-off-by: Brendan Lawlor <blawlor@clamsnet.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 6f8ef2b0c0788f71e821f2c56fc87c5a7173e081)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>