Replace listener-based mouse hit-testing with per-face overlay elements for face hover
detection, and migrate people store state to AssetViewerManager.
- Render invisible divs for each face as pointer-event hover targets
- Show white border + name tooltip on active hover
- Add face bounding box markers to photo sphere viewer (panorama support)
- Migrate boundingBoxesArray/showingHiddenPeople from people.store.ts to AssetViewerManager
- Delete people.store.ts (Faces interface moved to asset-viewer-manager)
Change-Id: Ied4c3894cc58874ed65725dcb8cc7ce86a6a6964
midzelis