Visual representation of deactivated server in lms list view and login view + inclusion of estonian college in lms list

- Refactoring on handling data in lms list view i.e. previous selected server.
- Visual notification to the user in login view about the deactivated status of the backend
- Visual notification to the user in lms list view about the deactivated status of the backend. While being on lms list view, the attempt to re-register to the server is being repeated every one hour.
- Handling in configuration and lms models the 403 and 404 error messages separately.
- Inclusion of estonian college in lms list view. Use of the appropriate logo.