Finish localization

- Add user preferences section to settings
- Make settings page available for all users
- Move log out button to settings page
- Make it possible for each user to choose their desired language

api/database/database.go

@@ -163,6 +163,7 @@ func MigrateDatabase(db *gorm.DB) error {
 		&models.VideoMetadata{},
 		&models.ShareToken{},
 		&models.UserMediaData{},
+		&models.UserPreferences{},
 
 		// Face detection
 		&models.FaceGroup{},