Removes re-export of config from configuration

Splits common Git constants into a separate file

Debounces Git extension close event to avoid eventing on shutdown

- adds tooltip and coloration to dates
- updates size and color of status icons

- adds preview badge to header
- updates account messaging
- updates remote overlay content

- adds watchers for repository changes
- adds banner content for account actions
- adds banner for connecting to GitHub

- adds subscription state
- adds loading and empty states
- adds account access badge
- moves filters to each section