[JIRAALIGN-2197] Features: Target Start and Complete sprints should be wiped out from the respective table in DB when feature changes the PI

Issue Summary

When we change the PI in the feature the target start and complete sprints are reset in the UI but not in the DB

Steps to Reproduce

There should be a feature that is assigned to some PI and has the target start and complete sprints set.

1. Open feature from preconditions
2. Change the PI and Save
3. Export the feature and validate if there are any values in the target start and complete sprints

Expected Results

Target start and complete sprint columns do not have any values set

Actual Results

Target start and complete sprints are still persisting in the work item

Workaround

Click Save 2 times after the PI is changed.