Add license selection dropdown with populated licenses

What does this MR do and why?

This is Part 3 of 3 of breaking up the original MR !103744 (closed)

In this MR:

• Update policy_rule_builder_v2.vue‎ to show license scan policy if selected
• Add dedicated license_scan_r‎ule_builder.vue‎ - (note this is derived from the logic embedded in policy_rule_builder.vue, it will go away after we remove the feature flag.

Screenshots or screen recordings

Video Demo

https://youtu.be/rCuqER6AkI4

Before & when flag off	After with flag on

How to set up and validate locally

• In a rails console enable Feature.enable(:license_scanning_policies)
• As a EE user Navigate to http://gdk.test:3000/<group>/<project>/-/security/policies
• Click New Policy button
• On the Scan Result Policy card click Select policy
• Add a license scan rule
• Verify license search works and preview on the righthand side updates

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 #371506 (closed)