Add devui package

[zalmoxisus]

Moving https://github.com/zalmoxisus/devui here as per #412.
There are 2 issues that should be fixed later:

• other packages in the monorepo should also be updated to the latest version of webpack. Because different versions of webpack, some plugins like html-webpack-plugin are failing.
• publishing storybook site should be nested with Docusaurus (putting that folder in assets/*).