HUE-2444 [search] Remove showDetails:false from the grid result dump

Deleted showDetails and details from the doc object
HUE-2448 [oozie]: fix a unicode exception

This can occur if the form error message contains unicode.
HUE-2447 [core]: ignore if document tables already exist

This migration can be quite slow if there are many documents.
This patch mitigates an error where the user interrupts the migration
while it's active and tries it again.