Summary:
It was manifesting as error "docactions.[Bulk]UpdateRecord for
non-existent record #1", and due to manualSort column having internal
state that wasn't properly cleared.
Test Plan: Added a test case that fails without the fix.
Reviewers: georgegevoian
Reviewed By: georgegevoian
Subscribers: georgegevoian
Differential Revision: https://phab.getgrist.com/D4183