Functionality for adding a file to a dataset

Overview of the feature request

Allowing for users of the package to upload a file to a dataset in a dataverse instance specified by the users.

What inspired the request?

Wanting to be able to use the package for an external website to be able to upload a file to a dataset within a dataverse instance.

What existing behavior do you want changed?

None

Any brand new behavior do you want to add to js-dataverse?

Uploading a file to a dataset

Any open or closed issues related to this feature request?

None

该 issue 未指定文件、测试或入口点。首先检查 package 现有的 dataset 相关 API 方法以及 Dataverse 文件上传 API；当用户能够将文件上传到用户指定的 Dataverse 实例中的 dataset 时，即视为完成。