Inspector Protocol: add Recordings.capturedInput event. Refactor backend to use
the same code path for serializing all inputs and a single input.

Closes #293.
Inspector: add de-bouncing for the dashboard replay state button.
Inspector: store receive raw inputs as they are captured into ReplayInputDataProvider.

Closes #293.
Create ReplayDashboardView for replay items.
Add eject button to ReplayDashboard to unload recordings.
Add cursor style on hover over ReplayDashboard buttons.