feat: Enhance addLessLoader

[edwardwang0302]

Support 4 ways to specific css-modules config.

1. Use "[local]--[hash:base64:5]" as default localIdentName

addLessLoader()

2. Compatible with the old way

addLessLoader({
  localIdentName: "[local]--[hash:base64:5]",
  // can't deal with getIdentName
}); 

3. Use cssModules property in loaderOptions

addLessLoader({
  ...,
  cssModules: {
    localIdentName: "[local]--[hash:base64:5]",
    ...
  }
}); 

4. Use optional param customCssModules

addLessLoader({},  {
  localIdentName: "[local]--[hash:base64:5]",
  ...
});