Bug 16424: Add framework support to advanced MARC editor

Bug 16424: Add framework support to advanced MARC editor

Keeps the selected framework, allows selecting another and validates the record using the correct framework. Contains additional minor tweaks to display proper error messages.

To test:
1. Add a record with a non-default framework in the basic editor.
2. Switch to advanced editor and make sure the settings menu displays the correct framework.
3. Save the record and confirm that the framework code did not change.
4. Change the framework and save the record again.
5. Verify that the framework code changed.
6. Change one framework to make an extra field mandatory.
7. Make sure that the field is required in the editor when the framework above is selected but not when another framework is selected.

Signed-off-by: Michal Denar <black23@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>