Selector: loadedAtFormatted (refactor)

The loadedAtFormatted selector for events state needs to be enhanced to base formatting on the currently selected timeZone from settings state. This will require removal of the selector from Events state into an area of shared selectors that compose selectors from multiple sources of state.

Acceptance Criteria:

• Should compose Events state
• Should compose Settings state
• Should format the loadedAt timestamp from Events based on the timeZone from Settings
• Should use date-fns library for formatting (functional, tree-shakable)