CSS classes exist twice: with and without antd-prefix

[mic-web]

Reproduce:

• http://localhost:6006/?path=/story/button--default
• open developer tools of your browser
• add ant-btn as another class to the button

Result:

This demonstrates that the mll-ant prefix works (mll-ant-btn applies), but it doesn't prevent the generation of the default classes (like ant-btn) -> ant-btn and mll-ant-btn-Styles exist

Expectation:

With a prefix being defined in antd.less, only classes with this prefix should be generated and being injected with this library.