allow teachers to specify certain fields in database activity as required

Note, all parts of the test need to be completed. Behat is currently unable to fill in some of the database fields we use (e.g. file, picture).

As this is a UI change, you'll need to check that the new UI elements display correctly in at least "clean" and "base" themes

1. Run behat tests
2. Create a new Database activity
3. Add required fields for:
   1. checkbox
   2. file
   3. latlong
   4. menu
   5. number
   6. picture
   7. radio
   8. text
   9. textarea
   10. url
   11. multimenu
4. Create templates
5. Go to add a new entry
6. Fill in all fields
7. Save and view
8. Confirm that the entry was added
9. Add required fields for:
   1. checkbox
   2. file
   3. latlong
   4. menu
   5. number
   6. picture
   7. radio
   8. text
   9. textarea
   10. url
   11. multimenu
10. Add another entry
11. Don't fill in any of the fields
12. Ensure that an error message appears next to all of the required fields, but not any of the others.
13. Delete all of the required fields
14. Add another entry
15. Don't fill in any of the fields
16. Confirm that the entry was added
17. Backup the activity
18. Restore the activity
19. Confirm that the required state for your fields was copied across