Split issues list refactor into CE and EE

What does this MR do and why?

This MR moves EE only features into EE directory for

• group/project issues list refactor (#322755 (closed)), behind feature flag vue_issues_list
• issue board filtered search bar, behind feature flag issue_boards_filtered_search

Changes:

• Moves epic, iteration, weight, blocking issues count, and health status features.
• Creates new files with new logic:
  • ee/app/assets/javascripts/issues_list/components/issue_card_time_info.vue
  • ee/app/assets/javascripts/issues_list/components/issues_list_app.vue
  • ee/spec/frontend/issues_list/components/issue_card_time_info_spec.js
  • ee/spec/frontend/issues_list/components/issues_list_app_spec.js

Screenshots or screen recordings

How to set up and validate locally

1. In rails console enable the feature flags

   Feature.enable(:vue_issues_list)
   Feature.enable(:issue_boards_filtered_search)

2. Visit any group or project issues list page such as http://127.0.0.1:3000/groups/flightjs/-/issues, and issue board
3. Test the MR

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.

Related to #322755 (closed)