[TASK] ADWD-1463, ADWD-1464 Update icons

- Add icons for most buttons
- Make logout link child of username
- Slightly change colors and margins
- Refactored custom SCSS into separate files
[FIX] Show Ort in Bistum editor
Merge pull request #140 from subugoe/ortfix

[FIX] Show Ort in Bistum editor