Add query string utilities to package and registries

What does this MR do?

This MR paves the way to implement connecting the search functionality in the Package and Container registry to the URL bar.

In this MR we are:

• Extending url_sync component to work with scoped slots
• Moving url_sync_spec to CE folder since is a CE component.
• Adding some shared utilities
• Extending registry_search to craft and emit up the new query object when appropriate.

In the next MR (!57251 (merged)) we will wire these components and utilities in both registries.

Screenshots (strongly suggested)

No visual changes

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because this is just a backstage preparation.
• [-] 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
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

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

Related to #324864 (closed)