Removed <hr/> markup in favor of utility classes

What does this MR do?

Follow-up to !28554 (comment 319636245).

• UX-wise: Ensures render consistency by leveraging utility classes vs. the prior <hr/> which each browser's style sheet may differ
• Tech-wise: Utility class use vs <hr/>

Screenshots

Though the backend wiring is not yet in place for this component to render, the render will look like this:

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