Bookmark modal polish

[bsclifton]

For use with these components:

• addEditBookmarkHanger
• addEditBookmark

The modal should be matching these mock ups by @bradleyrichter:
notice the following:

• arrow shape under the bookmark/folder name
• blue outline around input fields

when adding a folder:

when adding a new BM when no URL is present to start with:

[luixxiul]

@bradleyrichter are those mockups still valid?

[bradleyrichter]

closing this because it is already implemented as desired.