Pipeline Filter - Trigger Author, Branch Name

This issue is a scoped down issue of #15268 (closed), which has been promoted to epic &3286 (closed).

In this issue we will introduce filtering pipelines by Trigger Author and Branch Name.

Design specs can be found in the original issue or here https://gitlab-org.gitlab.io/gitlab-design/hosted/dimitrie/ce18054-pipeline-filters-spec-previews/

Proposal

This proposal will enable filtering the project pipeline list on:

• trigger author (high priority for scope)
• branch name (high priority for scope)