Refactors index_ml_models to use graphql

What does this MR do and why?

Refactors index_ml_models to use graphql

• Refactors index_ml_models.vue to use graphql
• SearchableList can display a search bar
• index_ml_models.vue now uses SearchableList to be consistent with other lists in the feature

Screenshots or screen recordings

UI changes are minimal, it is now better aligned with other pages

Before	After

How to set up and validate locally

How to set up and validate locally

1. Enable the feature flag and create a few models

   Feature.enable(:model_registry)
   
   p = Project.find_by(id: 1)
   100.times { |i| Ml::FindOrCreateModelService.new(Project.find_by(id:19), "model_#{54+i}").execute }

2. Navigate to <gdk>/<project>/-/ml/models.

   • Search and sorting should update the list without refreshing
   • navigation should respect the search
   • query should be updated with the new search query

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.