Project Quality no Junit test report empty state

🧩 Problem

Based on #337307 (closed), we will be adding a new project quality summary feature to the Analytics --> CI/CD page with metrics around different testing features.

For this case, and for future cases where the testing features may not be set up and therefore contain no metrics, we should come up with an empty state pattern to bring more awareness to the testing features and provide users with instructions of how to set up the features.

💡 Proposal

🎨 Designs: Screen 1 in design management below

🖌 Figma file: https://www.figma.com/file/RAA4AmQIY4aHhP8NvunbBj/Testing---Project-Quality-Summary?node-id=325%3A12381

Scenario / Use case

Scenario 1: My project has no tests set up nor any testing features, when I come to the project quality page, I want to be prompted to set them up so I can see the project metrics.

Illustrations

• All illustrations can be found in this Figma file

Set up / Learn more links

• Set up test runs: https://docs.gitlab.com/ee/ci/pipelines/settings.html#add-test-coverage-results-to-a-merge-request
• Set up test coverage: https://docs.gitlab.com/ee/ci/pipelines/settings.html#add-test-coverage-results-to-a-merge-request