As part of reactions and editing work, we're adding a new style of tooltip that
allows interacting with the content of the tooltip. `ContextualMenu` is closest
out of the things we have today, but it doesn't position in quite the way we
want and it's already quite complex.
To get started, let's first clone that to a new `InteractiveTooltip`.
Part of https://github.com/vector-im/riot-web/issues/9753
Part of https://github.com/vector-im/riot-web/issues/9716