Differentiate trigger jobs from regular jobs in the pipeline graph

What does this MR do and why?

We implement a new style for trigger jobs inside the pipeline graph. The pills are rectangle with rounded corners instead of pills and we add a badge that applies the Trigger job label. Also added some tests to make sure the badge and CSS class conditionals are applied.

Screenshots or screen recordings

Stage view

Before	After

Job dependencies view

Before	After

How to set up and validate locally

• Create a multi-project pipeline. Here is a simple config:

stages:
  - build
  - test
  - deploy

hi:
  stage: "test"
  script: "echo I run only on master"

hi2:
  stage: "deploy"
  script: "echo I run only on master"
  needs: ['hi']

trigger_other_project:
  stage: deploy
  trigger: "root/large-pipeline" # replace with another project

Then in the other project, any ci config will do:

job_from_other_project:
  script: echo hello

• Navigate to the pipeline graph
• Notice that your trigger job is taller, rectangle with rounded corners and has a badge Trigger job

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.