Move remaining groups page to vue3 rollout

What does this MR do and why?

This MR adds the pages.groups entry points behind the vue3_migrate_groups_entrypoint flag

Entrypoints

• pages.groups (EE only group page entrypoint at ee/app/assets/javascripts/pages/groups/index.js)
  • This entrypoint mounts 3 components: hand raise lead, end of trial modal, and amazon q

References

https://docs.gitlab.com/development/fe_guide/vue3_migration/#option-1-recommended-migrate-your-page-entrypoint-using-a-feature-flag-and-vue3_migrationyml

Closes: #630034 (closed)

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