Add conditions toHorizontal Rule and Line Break

[thupsi]

I think it would make sense to add conditions to Horizontal Rule and Line Break. All other UI elements have them, so I see no reason to ommit this functionality for these two elements.

Use case:
In some layout fields with conditions it's possible that all fields around and between certain UI elements could become hidden. In such cases the "orphaned" UI elements serve no puprose and just look weird.

[turnstylerj]

Would really like to see this as well!

[brandonkelly]

Added for 5.7! (c7cde6f)

[brandonkelly]

Craft 5.7.0 is out with that change.