Add approvers when editing scan result policies

What does this MR do and why?

Add approvers when editing scan result policies taking into consideration the existing feature flag. It also split a couple of fields which were previously only used for scan execution scan.

The approval data will only be used on the frontend in the follow-up MR.

Related issue: #351166 (closed)

Screenshots or screen recordings

Link to docs related to scan result policies

Link to docs related to scan execution policies

How to set up and validate locally

1. Enable scan_result_policy feature flag
2. Create a security project as described in the docs
3. Create a new scan result policy with the project owner
4. Log in with another user with lower privileges (like developer)
5. Trying to edit the policy will bring up the link to the documentation.
6. The same steps can be followed for scan execution policies.

** The instructions above are mostly related to the changes in regards to the link to the documentation. Approval data will be used on the frontend only in the follow-up MR.

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.