Adjust the webpackExclude check for node_modules

as mentioned inside the last blog post, it should do the following:

1. When building the App Worker for the neo.mjs framework itself, we want split chunks for all possible Apps inside the apps and the examples folder
2. When using neo.mjs as a node module, we only want split chunks for our own Apps (and not the examples & apps included inside the neo.mjs node_module). This part still needs testing.
3. When building the Online Examples, we trigger the build on the neo.mjs node_module, in which case we do want to get the content (This part works fine).

There is definitely a conflict for 2 and 3. Not sure if we can resolve this using magic comments or if we should adjust the webpack.config scripts.

Open for ideas!