Merge branch '541947-adds-warning-about-data-deletion' into 'master'

Adds a warning when a migration is deleting data

See merge request !286



Merged-by: Irina Bronipolsky <ibronipolsky@gitlab.com>
Approved-by: Irina Bronipolsky <ibronipolsky@gitlab.com>
Reviewed-by: Irina Bronipolsky <ibronipolsky@gitlab.com>
Co-authored-by: Leonardo Rosa <ldarosa@gitlab.com>