Fix TypeError: Cannot read property 'initTabs'

What does this MR do?

Adds a default value to the options argument in order to prevent errors when Pipelines is initialised without arguments. Adds tests to guarantee this does not happen again.

Adds back removed pipeline class to make the pipeline graph visible, js-pipeline-graph

Why was this MR needed?

In the places where Pipelines is initialised without arguments it throws an error: TypeError: Cannot read property 'initTabs'

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #25483 (closed) Closes #25493 (closed)