Adds candidate list to model detail

What does this MR do and why?

Adds candidate list to model detail

Adds paginated list of candidates associated to a machine learning model

Screenshots or screen recordings

Before	After

NOTE Version count has not been updated, it is supposed to still show 0.

How to set up and validate locally

1. In rails console enable the feature flag

   Feature.enable(:model_registry)

2. Create a model and a bunch of candidates

   p = Project.find_by_id(1)
   m = Ml::FindOrCreateModelService.new(p, "model_1").execute
   50.times { |i| Ml::CreateCandidateService.new(m.default_experiment, {}).execute }

3. Navigate to <gdk>/<project>/-/ml/models and select the model, then select the Version candidates tab

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.