Use Vue.js 3 compat mode for compliance center

What does this MR do and why?

This MR introduces Vue.js 3 compat feature flag for compliance center

References

Use Vue.js 3 compat mode for compliance center (#589152)

Screenshots or screen recordings

How to set up and validate locally

• Run FILTER=compliance_report_data SEED_COMPLIANCE_REPORT_DATA=1 bundle exec rake db:seed_fu and seed the group
• Open compliance center
• Toggle feature flag
• Observe everything still works

MR acceptance checklist

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

Related to #589152