Tooltips on mobile should be anchored & closable

[dotmacro]

Problem

There is no way for a mobile user to close a tooltip except by opening a different tooltip. While they're open, tooltips are anchored to the user's screen rather than the UI.

Note: The tooltips do disappear if the user opens the nav menu or switches away from the tab/page/screen showing the tooltip.

Solution

1. Tooltip should be anchored to the app (rather than user's screen).
2. Tooltip should be closable.