Move fkvalidator.sh to tools/dbutils

Moving the fkvalidator.sh script to tools/dbutils and make it stand
alone.
Also, defined common settings for dbutils in common.sh to be used by all
scripts.

Change-Id: I313a7066a7e7a70c8e97d3b13099d5f5695c33a5
Signed-off-by: Eli Mesika <emesika@redhat.com>
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=912305