Fix the css chunk issue in development and build issue in production.

[imranhsayed]

• Fix the chunk issue in development - Conflicting order issue

Mini css extract plugin Issues

• https://github.com/gatsbyjs/gatsby/issues/26486

• https://github.com/webpack-contrib/mini-css-extract-plugin/issues/250#issuecomment-415345126

• https://github.com/webpack-contrib/mini-css-extract-plugin/issues/250

• You can check to see what is using it by running yarn why mini-css-extract-plugin

• Possible solution to be tested, update the MiniCSSExtract plugin config in gatsby-node.js, as custom config

new MiniCssExtractPlugin({
  ignoreOrder: true,
}),

• Fix the build issue

[imranhsayed]

WIP PR