UI on GitLab to set default namespace | Model Selection

Task

Build a dropdown UI selector for #552075 (closed) in /-/profile/preferences#Behavior section of the user setting.

Here is a preliminary design of what we expect:

Design

You can find the GQL draft schema's in the implementation issue below:

• Query to get the list for the drop-down
• Query to get the currently selected user_preferences
• Mutation for the user_preferences