feat(otter): add working user removal route

gpodder_sqlite/src/repository/auth.rs

@@ -81,6 +81,16 @@ impl gpodder::GpodderAuthStore for SqliteRepository {
             .map_err(DbError::from)?)
     }
 
+    fn remove_user(&self, id: i64) -> Result<bool, AuthErr> {
+        let conn = &mut self.pool.get().map_err(DbError::from)?;
+
+        match diesel::delete(users::table.filter(users::id.eq(id))).execute(conn) {
+            Ok(0) => Ok(false),
+            Ok(_) => Ok(true),
+            Err(err) => Err(DbError::from(err).into()),
+        }
+    }
+
     fn get_session(&self, session_id: i64) -> Result<Option<gpodder::models::Session>, AuthErr> {
         match sessions::table
             .inner_join(users::table)