### 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_
raise InvalidArgument(
            "The x-amz-copy-source-range value must be of the form bytes=first-last where first and last are the zero-based offsets of the first and last bytes to copy",
            ArgumentName="x-amz-copy-source-range",
            ArgumentValue=copy_source_range,
        )
    if begin is None or end is None or begin > end:
        raise InvalidArgument(
            "The x-amz-copy-source-range value must be of the form bytes=first-last where first and last are the zero-based offsets of the first and last bytes to copy",
            ArgumentName="x-amz-copy-source-range",
            ArgumentValue=copy_source_range,
        )
    if begin > last:
        
        raise InvalidRequest(
            "The specified copy range is invalid for the source object size",
        )
    elif end > last:
        raise InvalidArgument(
            f"Range specified is not valid for source object of size: {object_size}",
            ArgumentName="x-amz-copy-source-range",
            ArgumentValue=copy_source_range,
        )
    return ObjectRange(
        content_range=f"bytes {begin}-{end}/{object_size}",
        content_length=end - begin + 1,
        begin=begin,
        end=end,
    )
def get_full_default_bucket_location(bucket_name: BucketName) -> str: