Enable transpilation of non-CJS packages

[willviles]

It'd be great if Payload exposed a simple way to transpile modules, similar to Next.js' transpilePackages array in next.config.js.

This would enable any non-compiled esm or ts package to be used by Payload.

Personally, this would be a massive win. It'd allow me to configure my Turborepo so there's no build step to compile all my esm/ts packages down to cjs and would speed my dev workflow up a huge amount!

I've hacked it around with a custom webpack config using swc-loader.

config.admin.webpack = (config) => {
  const transpileModules = ['@acme/ui']

  config.module.rules.push({
    test: /\.(t|j)sx?$/,
    exclude: new RegExp(`node_modules/(?!(${transpileModules.join('|')})/).*`),
    use: [
      {
        loader: 'swc-loader',
        options: {
          jsc: {
            parser: {
              syntax: 'typescript',
              tsx: true
            },
            transform: {
              react: {
                runtime: 'automatic'
              }
            }
          },
        },
      },
    ],
  })
}

This setup works fine when running the server, but when trying to generate types or the GraphQL schema, it fails because the CLI commands aren't bundled with Webpack.

Originally posted by @willviles in #2106 (comment)