Pipeline filter by trigger author

What does this MR do?

This MR introduces the ability to filter pipelines and still poll the api with the correct query params. This feature will live behind filter_pipelines_search feature flag currently disabled by default.

For this MR the ability to filter by trigger author is introduced. Another MR will be created to filter by branch, and then the feature flag will be set default enabled true.

Related issue: #215367 (closed)

triggerauthor-filter

filter-trigger-author-list

Screenshots

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