Breakdown tests in pipeline editor app new architecture

What does this MR do?

This is part 2 of a 2 parts MR sequence that are targeting a feature branch: 292930-breakdown-pipeline_editor_app-into-smaller-components and not master. This MR adds the tests to thee feature branch for the new architecture of the pipeline editor.

IMPORTANT: Please note that this MR aims at restructuring the architecture and not improving tests on an individual basis. I have tried to move the file as close as possible as what already existed to facilitate review. Granular changes would be better suited in follow-up MR so they can be discussed properly and not missed. I have left a bunch of comments on each file to point out the changes I have make to draw attention there. Feel free to point out individual tests, but they might need to be done in a follow-up. 🙇🏼

Part
1: Merge the code change in feature branch
2: Merge test suites changes in feature branch (You are here)
3 Merge feature branch into master

This refactor has more context in the architectural discussion that preceded this change. The gist of it as as follow:

• Breakdown the pipeline_editor_app component into smaller components that represent part of the new section.
• The component structure is as follow:

pipeline_editor_app 
  -> pipeline_editor_home
       -> pipeline_editor_header
       -> pipeline_editor_tabs
         -> text_editor
         -> pipeline_graph
         -> ci_lint
       -> commit_section

• Use provide/inject for all static values at the top level
• Have graphQL with apollo fetch the top level data, then pass it down using props
• Add events where needed for children component to emit their changes upward

Couple of things to note while reviewing:

• This looks bigger than it is. A lot of code is just moved.
• To facilitate your review, start by looking at pipeline_editor_app_spec so you can see what has been externalized to different components
• Then you can go top-down following the architecture plan I left above of each component

This does not change any User facing interface, so it doesn't require a changelog.

Screenshots (strongly suggested)

No visual changes. Here is a video of all the features still working

authoring

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

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team