Add additional pipeline information to packages list api endpoint

Merged Nick Kipling requested to merge 197923-add-pipeline-to-packages-list-api into master

What does this MR do?

To support the frontend changes in #197923 (closed), the Packages API list endpoint needs to be updated to return more pipeline information - specifically the user who triggered it.

This MR adds that information into the Package Grape Entity.

Screenshots

Added deprecation notice to the docs
Screenshot_2020-03-27_at_09.38.39

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

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
Edited by Nick Kipling