Add policy scope feature flag on project level

What does this MR do and why?

Previously policy scope feature was available only on group level.

It will be also available on project level, feature flag is required on project level as well

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

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***NO VISUAL CHANGES***

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

Related to #432513 (closed)