Bug 36815: (follow-up) Fix logic for new languages

Bug 36815: (follow-up) Fix logic for new languages

If a notice doesn't already have any data in it we weren't able to use
the object to lookup the sample.. with this patch we now always load the
samples if they exist for each installed and enabled language,
regardless of whether there's already a notice stored in that language.

Test plan
1. Install Spanish by running koha-translate --install es-ES from inside
   the kohashell
2. restart all
3. Set TranslateNotices to Allow
4. Verify that the Spanish-language sample_notices.yml exists
5. Open a notice that has at least one Spanish default notice defined
6. Confirm you see the 'View default' button for the spanish notice and
   that the displayed notice is indeed the spanish translation

Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>