Provide a label for 'Scheduled Pipeline' in the pipelines overview page

What does this MR do?

This adds a schedule label on pipelines when their origin was a schedule. This helps recognize them more easily. We can also hover over the label fore more details as to why this label was applied and you can click on the label so that it takes you to the schedule page.

Screenshots

Before

After

Issue: #24241 (closed)

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