Dependency List - follow-up to preliminary frontend implementation

See #10075 (closed) for full context.

This is a follow-up of #11059 (closed) to track the remaining frontend work to be done to satisfy #10075 (closed). This is closely linked to #11396 (closed).

Requirements

• Full list of possible report_status responses from backend: gitlab-org/gitlab-ee#11759
  • job_not_set_up Design
  • job_failed Design
  • no_dependency_files Design
• Final ~"UX ready" designs
• Full list of supported package types (e.g., npm, gem, maven) and corresponding display strings (e.g., Composer (PHP)) This is now unnecessary, as the backend will provide display-ready packager strings directly: https://gitlab.com/gitlab-org/gitlab-ee/issues/10075#note_174648809.
• SVG(s) for empty state(s): illustrations/Dependency-list-empty-state.svg
• BoM documentation URL This is actually more relevant for #11396 (closed).

Tasks

• Implement finalised edge cases
• Write component tests
• Remove all TODO code (mocked axios)
• Use repo-relative string for dependency file location link text