Fix for slow Quicklook Preview Catalina

I've spent hours trying to problem solve the slow rendering of .jpg previews in Finder, only to find out that quitting Google Filestream which I have to use for work solved the issue immediately.

You'll need to re-download all your Filestream data (if working offline and make sure you're fully sync'd before doing this), but if you have this problem:

• Exit Google Filestream
• Restart
• Check quicklook previews are snappy again

If so:

• Go to ~/Library/Application Support/Google
• Delete the whole of the FS folder
• Delete ~/Library/Preferences/com.google.filestream
• Restart
• Redownload Filestream and relogin

I'm not sure why Google Filestream was messing around with quick look - it even affected files on the Desktop, supposedly outside of Google's 'control' as not in the Filestream folder.

But everything working again now - so relieved to have my Mac back properly.