Add pipeline resource

What does this MR do?

Adds Pipeline resource with API support to QA suite

Small refactors to how the index/show/new pages interact with eachother using dynamic element validation

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content