Move `showEditFaces` state to `assetViewerManager` so the edit faces
panel open/close state is globally accessible. Add Escape key handling
to `PersonSidePanel` that closes the assign-face sub-panel first, then
the edit faces panel. Guard the asset viewer's global Escape-to-close
action so it doesn't fire while either face panel is open.
Change-Id: I0c947fe0758aef0eac473f4cc72f6a3b6a6a6964