Geo Primary Verification List: Avoid full page reload when switching models

Why are we doing this work

This work will be behind feature flag geo_primary_verification_view

This issue is focused on refactoring the list page such that we load the data asynchronously when changing the selected models instead of doing a fullpage reload.

Relevant link

Raised in !209761 (comment 2848559523)+

Implementation Guide

1. Remove the model_class_data from the HAML template
2. Rename the modelClass props to defaultModel in ee/app/assets/javascripts/admin/data_management/components/app.vue.
3. Create a data property for activeModel in ee/app/assets/javascripts/admin/data_management/components/app.vue
4. Update relevant code to use the activeModel instead of the modelClass.
5. Update the handleListboxChange to update the activeModel and refetch the data.