Transfer namespace to organization user flow

- Work item: https://gitlab.com/groups/gitlab-org/-/work_items/20135
- FigJam: https://www.figma.com/board/sgIyfSDPLnbC4NreNNbP9C/Transfer-to-org-user-flow?node-id=0-1&t=f4WmUcbyW09nShxj-1

It covers:
- Notification timeline
- Pre-transfer flows for namespace Owners and namespace members (enterprise users and personal users)
- During transfer and post-transfer flows

Видео Transfer namespace to organization user flow канала GitLab Unfiltered