cases are saved during creation even when aborted

[vincetrumental]

Describe the bug
When I create a new case, and I cancel the creation, the case is saved anyway

To Reproduce
on version 7.13.0 (on-prem docker)

1. Click on "Relevancy Cases" -> "Create a case" or "+ Add new"
2. at some point before FINISH step, click on the top-right cross in the pop-in window
3. go to the cases lists, a new case appears named "Case X" or "Case: X" (the colon depends on which button you clicked to create the case)

Expected behavior
no case is created until you click "Finish"