Calling FS + writeFile causes massive memory usage due to log

[Balearica]

The worker.FS function logs all arguments it receives. While this would be fine for a function that only has boolean/integer/etc. arguments, this function is used to write massive files. This log function is therefore massively inflating memory usage.

https://github.com/naptha/tesseract.js/blob/master/src/worker-script/index.js#L60-L63

One test I ran showed that writing eng.traineddata to the virtual filesystem using FS peaked Node memory usage at 700MB, which is ridiculous for writing a ~20MB file. The log call should be modified to remove args.