Implement the Vue todos app's author filter

What does this MR do and why?

Implement the Vue todos app's author filter

Creates the AuthorToken component for filtering the todos by author in the new Vue app.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Suggestions list	Selected author

How to set up and validate locally

1. Enable the todos_vue_application feature flag: echo "Feature.enable(:todos_vue_application)" | rails c.
2. Navigate to the Vue todos app: http://gdk.test:3000/dashboard/todos/vue.
3. Filter out todos using the filtered search component.

Related to #483052 (closed)