equals method
Checks if this public key is equal to another
Implementation
@override
Future<bool> equals(p2pkeys.PublicKey other) async {
if (other is! EcdsaPublicKey) return false;
// Compare the Q points
final q1 = _key.Q!;
final q2 = other._key.Q!;
return q1.x!.toBigInteger() == q2.x!.toBigInteger() &&
q1.y!.toBigInteger() == q2.y!.toBigInteger();
}