Export to zng creates missing errors

[jameskerr]

This is maybe not a bug, but certainly undesirable behavior. Watch the video to reproduce.

The issue is that when you export the results while having some columns selected with the column picker, you end up with missing errors.

The solution may be to change the query we make when exporting.

https://user-images.githubusercontent.com/3460638/154568060-e5759414-44e8-424a-a1e6-3ea273c7cc32.mov