Refactor group issues page from Haml to Vue

What does this MR do?

This MR refactors the group issues page from Haml to Vue, as part of the refactor #322755 (closed) behind the feature flag vue_issues_list.

The project issues page has been converted to Vue, using issues_list_app.vue — this MR reuses this component for the group issues page too as most of the logic is the same.

Screenshots or Screencasts (strongly suggested)

How to setup and validate locally (strongly suggested)

1. In rails console enable the feature flag

   Feature.enable(:vue_issues_list)

2. Visit any group issues page http://127.0.0.1:3000/groups/h5bp/-/issues
3. Test the page

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Related to #322755 (closed)