when a a second modal is opened over another modal, the enforce fupocus of the first modal prevents inputs in the second modal from being focused.

workaround: set no-enforce-focus to true on lower modal's

fix: listen for $root modal open events and disable enforce focus dynamically if another modal opened with a higher z-index, and re-enable on $root modal close events. z-index is the only way to determine the front most active modal