Bug 26065: Move translatable strings out of marc_modification_templates.tt and into...

Bug 26065: Move translatable strings out of marc_modification_templates.tt and into marc_modification_templates.js

This patch removes the <script> block in the MARC modification
templates template in which strings are defined for translation
purposes.

Strings are now in place in the JavaScript file and wrapped in the new
__() function.

To test, apply the patch and clear your browser cache if necessary.

- Perform some actions which will trigger translated strings, for
  example:
  - Create a new template
  - Add an action to the template and then delete it.
    - The confirmation should appear correctly
  - Add an action. Select "Copy" as the operation and click "Add action"
    without filling in any fields.
    - You should see a message, "Both subfield values should be filled
      or empty"

TESTING TRANSLATABILITY

- Update a translation, e.g. fr-FR:

> cd misc/translator
> perl translate update fr-FR

- Open the corresponding .po file for JavaScript strings, e.g.
  misc/translator/po/fr-FR-messages-js.po
- Locate strings pulled from
  koha-tmpl/intranet-tmpl/prog/js/marc_modification_templates.js for
  translation, e.g.:

  msgid "Both subfield values should be filled or empty."
  msgstr ""

- Edit the "msgstr" string however you want (it's just for testing).
- Install the updated translation:

> perl translate install fr-FR

- Switch to your newly translated language in the staff client and
  repeat the test plan above. The translated string should appear.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>