Exclude folders from list dropdown in Save To List dialog

GCP-7603

Reviewer: Crisjaira Villarino
Added unit test for excluding showing folders in Save To List dialog

GCP-7603

Reviewer: Crisjaira Villarino
Reduced Sonar violations
1. Use Collections.isEmpty for checking list size
2. Preserve original exception in exception handler
3. Local variables should not shadow class variables
4. Follow variable naming standard

GCP-7603

Reviewer: Crisjaira Villarino
Modified assertion message in order to be more descriptive, as result of code review

GCP-7603

Reviewer: Crisjaira Villarino