Adds timeline, calendar, message renderers. Fix map renderer. Fix lineChart renderer. Other improvements

• Adds timeline, calendar, message renderers.
• Fixes the map renderer to work with edges.
• Fixes LineChart renderer (now checks for NaN, fixed Person.age computed var).
• Adds a ContextualBottomBar for edit-mode delete actions
• Fixes visibility of rich-text-editor title textfield on macOS
• Adds ActionOpenViewWithUIDs to enable opening a view with specific items (used for timeline grouping and calendar press action)
• Settings now has a Settings.shared instance that is safe to use on the main thread. On other threads instantiate with Settings()
• Update DateModified on using Item.set(...)
• Other improvements