Adds compliance framework dropdown for policy scope

What does this MR do and why?

This initial MR for #428494 (closed)

Policy scope components is not finished in this MR (behind feature flag).

This issue is broken down into multiple MR's for better review.

This MR adds compliance framework dropdown

New compliance framework dropdown and form for creation of new compliance frameworks for scan result policy and scan execution policy..

Popover with project list like in design will be added later as soon as query for this is available.

You can see full list of MR's in parent issue in Related merge requests section

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Description	UI
Dropdown basic action	dropdown.mov
Create new framework	new framework.mov

How to set up and validate locally

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

1. Enable Feature Flag

   Feature.enable(:security_policies_policy_scope)  

2. Go to a Group -> Secure -> Policies -> New policy -> New scan result/execution policy -> check Policy scope section is there.

3. Go to Project -> Secure -> Policies -> New policy -> New scan result/execution policy -> check Policy scope section is not there.

4. Try to create new compliance framework from dropdown

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

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

Related to #428494 (closed)