Issue Summary

Features: User shouldn't be able to assign feature to the parent in different PI

Steps to Reproduce

Preconditions: There should be an epic that is assigned to the progam1 and PI1. There should also be a feature that has Program1 and PI2.

1. Open feature from preconditions
2. Select epic from preconditions as a parent
3. Save

Expected Results

When selecting Epic which is in a different PI than Feature, the modal appears with the message: "This Epic does not align with the feature's program increment.  Selecting this Epic will remove your existing program increment selection" and buttons 'Yes, select it' and Cancel.
On click 'Yes, select it' Epic is displayed in Parent field, PI field is reset to Unassigned backlog (as Parent Epic can have multiple PIs selected)
On click 'Cancel' - no changes in the Parent field.

We need to implement this logic on Parent object change for Capabilities, Features (change Epic/Capability)
And on initial assignment of Feature to Epic/Capability.

In case Feature (Capability) is in Unassigned Backlog - no validation needed.

Actual Results

The item is normally saved what can cause a misalignment of the work items between the PIs.

Workaround

Align the PIs manually