Replace deprecated dropdown on new project page

What does this MR do and why?

• Replace dropdown menu UI for group selection on Create new project page.
• Replace gl-dropdown to gl-collapsible-listbox. The gl-dropdown is deprecated and does not show long names correctly.
• Fixes #427683 (closed)

Screenshots or screen recordings

Before	After
Screen Recording 2023-12-12 at 13.30.42.mov	Screen Recording 2023-12-12 at 13.25.11.mov

How to set up and validate locally

1. Create a new group with a long name containing only characters and underscores
2. Create a new project and try to assign this group --> name is truncated in dropdown
3. Apply changes from this branch
4. Try to assign group again --> Dropdown has horizontal scrollbar even for non-breakable names

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.
•   @oksanakohuch-ext
•   @stingrayza