db: cleanup: removing obsolete scripts

backup.sh and restore.sh are obsolete.
engine-backup should be used for backup and restore.
create_db.sh is not used since 3.3.
encryptionvalidator.sh is not used since 3.3.
exportDbSchema.sh is not used.
*_schema_checksum.sh are not used.

Change-Id: I4133c2f442bef91bebb427b7acac34cad278f396
Signed-off-by: Eli Mesika <emesika@redhat.com>
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>