allow to execute a part of the module graph at build time
e. g. to generate code or other assets
loaders have access to that via `this.importModule(request, options)`
to keep track of runtimes, used exports depending on runtime
modules can have different hashes and generated code depending on runtime
chunks are only considered as equal for MergeDuplicateChunks and SplitChunks when exports used in contained modules are equal
added `optimization.usedExports: "global"` to opt-out from used exports analysis per runtime
added `splitChunks.usedExports` and `splitChunks.cacheGroups[x].usedExports` to enable/disable used exports comparing for modules
`splitChunks.usedExports` defaults to `true` in production