Dependency List - Preliminary Frontend implementation

See https://gitlab.com/gitlab-org/gitlab-ee/issues/10075 for full context.

This issue is to track the Frontend implementation that will happen in %11.11 to reduce the weight of the final implementation for https://gitlab.com/gitlab-org/gitlab-ee/issues/10075

Goals

• Put everything behind a feature flag
• Use Mock Data (either from a mocked JSON or a mocked API, see: https://gitlab.com/gitlab-org/gitlab-ee/issues/11060) to
  • Requirement: Work out the data schema and the API with backend
• Preliminary design should be implemented:
  • Requirement: Get a consensus on the design with UX

Implementation plan

1. Bootstrap the new views behind a feature flag (page bundle entrypoint)
2. Implement the design as it stands with all functionality required by UX, mock out the responses