Add vue package app to groups

What does this MR do?

This MR moves current groups/packages page to a legacy partial and add :vue_package_list feature flag to load the new component, it also extend the component to accept a groupId to properly call the API.

This MR is contextual to the work being done in and around !18860 (merged)

'Twin MR': !19351 (merged)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Part of #33905 (closed)