[JIRAALIGN-1594] Import: Test case import produces duplicates

Issue Summary

Duplicate test cases are created during import if the story linked to it has an identical story name.

Steps to Reproduce

1. Create a Story several times in a program and make sure all stories have the same name. (Case sensitivity doesn't matter)
   
2. Create a test case import and enter only 1 test case
3. Make sure that the test case is linked to a story name that we created in step 1.
4. Import the test case
   

Expected Results

Only 1 test case imported.

Actual Results

The single test case is duplicated based on the number of stories with the same name that is linked to it.

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available