Fix strategy input rerendering on name update

What does this MR do and why?

Fix strategy input rerendering on name update

Unique key is triggering the component rerender. Use id or index instead.

Changelog: fixed

References

!202301 (merged)

Screenshots or screen recordings

Before	After
Screen_Recording_2025-09-01_at_14.25.21	Screen_Recording_2025-09-01_at_14.13.32

How to set up and validate locally

1. Navigate to Project -> Deploy -> Feature flags.
2. Select View user lists and create a new list.
3. Create a new feature flag with the "Type" "User List".
4. Type into the name field and check that the user list input isn't rerendered.

MR acceptance checklist

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Related to #386431 (closed)