[Server][DBClientHatohol] Expand ItemInfo to store hostgrup information.
[Server][DBClientHatohol] Use table variable.

Currently, table variable is used when DBClientHatohol functions get
data using join tables.
But, we will use row table name instead of table variable.
[Server][DBClientTest] Add new test data.
[Server][testDBClientHatohol] Store hostgroup information before the
test begins.
[Server][FaceRest] Add hostgroup information to response "items" json
data.