### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

- Localstack fails with HTTP 500, error code "InternalError", message "not enough values to unpack (expected 2, got 1)" when `CopySource` is an invalid string for `copy_object` API.

### Expected Behavior

- For the same API `copy_object`, the cloud fails with HTTP 400, error code "InvalidArgument".
- Localstack should handle invalid `CopySource` i.e., it is a dictionary with one value or an invalid string not adhering to "{bucket}/{key}" format.

### How are you starting LocalStack?

With a `docker run` command

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    docker run localstack/localstack

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

    botoclient.copy_object(CopySource="Invalid_random_string", Bucket="test_bucket", Key=key) 


 test_bucket is a valid bucket.  

### Environment

```markdown
- OS: Ubuntu 22.04.2 LTS
- LocalStack: 2.1.0
- boto3: 1.28.6
```


### Anything else?

_No response_
)
        result = aws_client.s3.get_bucket_lifecycle_configuration(Bucket=s3_bucket)
        snapshot.match("get-bucket-lifecycle-conf", result)
        key = "test--expiry"
        put__1 = aws_client.s3.put_(Body=b"test", Bucket=s3_bucket, Key=key)
        version_id_1 = put__1["VersionId"]
        response = aws_client.s3.head_(Bucket=s3_bucket, Key=key)
        snapshot.match("head--expiry", response)
        parsed_exp_date, parsed_exp_rule = parse_expiration_header(response["Expiration"])
        assert parsed_exp_rule == rule_id
        # use 
        assert (
            current_exp_days - 1
            <= (parsed_exp_date - response["LastModified"]).days
            <= current_exp_days + 1
        )
        key = "test--expiry"
        put__2 = aws_client.s3.put_(Body=b"test", Bucket=s3_bucket, Key=key)
        version_id_2 = put__2["VersionId"]
        response = aws_client.s3.head_(Bucket=s3_bucket, Key=key, VersionId=version_id_1)
        snapshot.match("head--expiry-noncurrent", response)
        # This 
        # See 
        # Note 
        # prov
        assert "Expiration" not in response
        # if y
        response = aws_client.s3.head_(Bucket=s3_bucket, Key=key, VersionId=version_id_2)
        snapshot.match("head--expiry-current-with-version-id", response)
        assert "Expiration" not in response