Improve token access add form

What does this MR do and why?

Improve token access add form

Show form feedback when group/project path is already in allowlist
Replace text box with searchable collapsible listbox
Get groups and projects via graphql, list them in the box
Once selected, add group or project to allowlist when form is submitted

Changelog: changed

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Screenshots or screen recordings

Before	After
Screen_Recording_2024-06-07_at_11.55.15	Screen_Recording_2024-06-07_at_12.25.45

How to set up and validate locally

1. navigate to a project
2. in the sidebar, choose Settings => CI/CD
3. expand the Job token permissions section (previously known as Token Access)
4. add groups and projects to the project's allowlist
5. the form should:
   • show a list of groups and projects
   • be searchable
   • warn you if you try to add the same group/project twice
   • add the selected group/project to the allowlist on submit
   • be cleared on cancel

Related to #415519 (closed)