Is there a way to archive Live Photos to the filesystem on macOS?
What I have found is the ability to export the .JPG and .MOV versions of the same photo to a folder in Mac.

Go to File-> Export-> Export unmodified original. Then chose the folder. This created a .JPG and a .MOV file with the same first name. I imported both of them together using cmd+shift+I and they appeared as one. 

I checked (but not thoroughly) through Pictures-> Photos Library.photoslibrary right click-> show package contents. Couldn't find mov files. I recommend someone to check it.