Organization list view in "Your work" - build list

Build the organizations list view in Your work.

Designs

Originally from: #410343 (closed). List view, in specific, is visible here. Figma file.

Implementation guide

1. Add app/assets/javascripts/organizations/index/components/app.vue
2. Add mount element to app/views/organizations/organizations/index.html.haml
3. Export mounting function from app/assets/javascripts/organizations/index/index.js
4. Use #417892 (closed) to get list of organizations
5. Use GlAvatarLabeled to render list of organizations
6. Add New organization button to the page header
7. Add empty state using GlEmptyState. Illustration: https://gitlab-org.gitlab.io/gitlab-svgs/illustrations?q=illustrations%2Fempty-state%2Fempty-organizations-md.svg