3.0.0

[mickael-menu]

Checklist of breaking changes for the 3.0.0.

• Isolate every non-public APIs shared among Readium modules into a private internal module.
• Replace synchronous APIs with async variants on iOS 13+
  • @_disfavoredOverload can be used for this, like in GRDB

Navigator

• Extract the VisualNavigator's presentation and goLeft/goRight in a new interface dedicated to "flowing" publications, as it wouldn't make sense for a video-based publication.
• didTap event should not trigger anymore from a click event, and we need new callbacks for mouse events.

Shared

• Remove the legacy compressedLength Link property.