UX: minor share report popup improvements (PR #49)

This change will make sure color schemes are honored, add type="text" to the <input> element, and reuse the “close” icon button from core’s share-link popup.

Before: Screen Shot 2020-05-18 at 4 26 16 PM

After: Screen Shot 2020-05-18 at 4 26 27 PM

GitHub

no need for “btn” in class here, it’s already present with d-button