function getFirstModuleChunk(moduleId) {
    const moduleChunkPaths = moduleChunksMap.get(moduleId);
    if (moduleChunkPaths == null) {
        return null;
    }
    return moduleChunkPaths.values().next().value;
}
Returns the first chunk that included a module.
This is used by the Node.js backend, hence why it's marked as unused in this
file.