Flow file monitor should not traverse into `node_modules`

[mhsdesign]

There is currently no guarding against monitoring everything out of node_modules. As this is such a common preserved folder i would not expect anyone sane for using it for real. And in turn expect flow to not traverse into it while listening for changes:

https://github.com/neos/flow-development-collection/blob/dad697040135e49a9efec11e6973ceecf27bfb50/Neos.Flow/Classes/Monitor/FileMonitor.php#L347-L354

I did not measure the impact but i simply cannot imagine that accidentally monitoring node_modules is ever a good idea.