Shared Highlighting

Shared Highlighting is a feature allowing users to generate and share links to specific parts of a web page, and to open these links.
When a Shared Highlighting link is opened, the page scrolls to and highlights the passage specified by the sender.

This feature is being developed across platforms. This component hosts the common code shared by all platforms.
For now, this mainly consists of metrics, but will encompass more parts of the feature in future milestones.