feat: finished new logging feature

lib/core/logging/utils/redaction_utils.dart

@@ -0,0 +1,22 @@
+(String username, String obscuredUrl) splitRedactUserId(String userId) {
+  final parts = userId.split('@');
+  if (parts.length != 2) {
+    return ('unknown', 'unknown');
+  }
+
+  final username = parts.first;
+  final serverUrl = parts.last;
+  final uri = Uri.parse(serverUrl);
+  final hostLen = uri.host.length;
+  final obscuredUrl = uri.scheme +
+      "://" +
+      uri.host.substring(0, 2) +
+      List.filled(hostLen - 4, '*').join() +
+      uri.host.substring(uri.host.length - 2, uri.host.length);
+  return (username, obscuredUrl);
+}
+
+String redactUserId(String userId) {
+  final (username, obscuredUrl) = splitRedactUserId(userId);
+  return '$username@$obscuredUrl';
+}