repeated `sealed_value_optional` get's wrapped into Seq[Option]

[goldlil]

When using oneof in ScalaPB with the sealed_value_optional and using it as single message it get's wrapped into an Option, but repeated fields get wrapped as Seq[Option[T]] instead of the expected Seq[T].

This inconsistency differs from how ScalaPB handles other repeated fields/messages (without oneof), which are typically wrapped directly in Seq[T]. Here’s a breakdown of the problem and generated code behavior:

message TestMessage {
  oneof sealed_value {
    StringWrapper1 bla = 1;
    StringWrapper2 xa = 2;
  }
}

message TestMessage2 {
  oneof sealed_value_optional {
    StringWrapper3 blzza = 1;
    StringWrapper4 xazz = 2;
  }
}

message ProperMessage {
  google.protobuf.StringValue test = 1;
  google.protobuf.Timestamp test2 = 2;
  google.protobuf.BoolValue test3 = 3;
}

message BiggerMessage {
  TestMessage message = 1;                 // -> TestMessage  = TestMessageMessage.SealedValue.Empty
  repeated TestMessage messages = 2;       // -> Seq[TestMessage] = Seq.empty

  TestMessage2 message2 = 3;               // -> Option[TestMessage2] = None
  repeated TestMessage2 messages2 = 4;     // -> Seq[Option[TestMessage2]] = Seq.empty

  repeated TestMessage2 messages3 = 5;     // [(scalapb.field).type = "scala.collection.immutable.Seq[...TestMessage2]"]
  // ^^ does not work because sealed oneofs can't be type mapped

  repeated ProperMessage test3 = 6; // -> generated -> Seq[ProperMessage] = Seq.empty

}