Bug 16163: Show message if there are no dictionary definitions

 Bug 16163: Show message if there are no dictionary definitions

To test:
1) Go to Reports -> View dictionary
2) Ensure you have no definitions
3) A message should show saying 'There are no saved definitions. Add a definition to the dictionary.'
4) Click the link to add a definition. Confirm this takes you to the form to add a new definition.

Sponsored-by: Catalyst IT
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan A Gallagher <brendan@bywatersolutions.com>