Add admins

- added a "add admins" feature to the admin dashboard page
- moved the admin dashboards page from the user settings page to its own page
- added email confirmation at account creation
- added email notification when a project is approved or denied

todo: 
- refactor admins so admin access to pages is more clean/secure
- add email confirmation to when project is favorited
- add "do not notify when project is favorited" to settings