Add function which captures a 200x200 section of a Frame and encodes it as a data URI (base64 encoded PNG).
Scale down FrameCamera images if their width or height exceeds 1000px.
Update FrameCamera to work with upstream changes.
Implement protocol message for sending captured image data URIs to the frontend.
For now, capture images when key press events are dispatched.
Create data provider to manage captured screenshots in the old WebInspector UI.
Don't wrap base64 encoded captured images with 'url()' (as if they were to be used in a CSS rule).
Display captured screenshots in ReplayOverviewPreview.