Separate feature categories in PipelinesController

What does this MR do?

There are several actions that are currently attributed to continuous_integration that should not be.

This defines separate categories for all actions in the pipelines controller.

This will also cause the specs to fail when adding a new action.

Saw this when looking into the controller action discussed in gitlab-com/www-gitlab-com#10442 (closed)

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because this change is not user facing.
• 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