[server][HostResourceQueryOption] Make a full column name with its table name.
[server][HostResourceQueryOption] Use a helper method to make code simple.
[server][FaceRest] Remove a mechanism to eliminate duplicated triggers.

Now getTriggerList never generates duplicated entries, because
DBClientHatohol doesn't use a join expect when a host group ID
is specified. Of course, in that case (using a host groupd ID),
duplicated entries are not generated in principal.
[server][FaceRest] Remove a mechanism to eliminate duplicated events.

Now getEventList never generates duplicated entries, because
DBClientHatohol doesn't use a join with the hostgroup table
expect when a host group ID is specified. Of course, in that case
(using a host groupd ID), duplicated entries are not generated
in principal.
[server][FaceRest] Remove a mechanism to eliminate duplicated items.

Now getItemList never generates duplicated entries, because
DBClientHatohol doesn't use a join with the hostgroup table
expect when a host group ID is specified. Of course, in that case
(using a host groupd ID), duplicated entries are not generated
in principal.
[server][FaceRest] Remove a class that is no longer used.
[server][HostResourceQueryOption] Rename a method to improve naturalness in the contexts.

isOnlyOneTableUsed ->
isHostgroupUsed
[server][HostResourceQueryOption] Fix a parameter name to be fit to its type.
[server][HostResourceQueryOption] Add an API description.
[server][HostResourceQueryOption] Simplify the implementation.
[server][HostResourceQueryOption] Add a new method: getHostgroupColumnName().
[server][HostResourceQueryOption] Add a new method: useTableNameAlways().

This is supposed to be used in getEventList() that does a join operation.
[server][HostResourceQueryOption] Make useTableNameAlways a const. method so that the caller can use it even if it's a const instance.
[server][DBClientHatohol] Fix a problem in which an SQL statement causes an error due to missing of the table name.
[server][HostResourceQueryOption] Eliminate the user of the input parameter to be code simple.
[server][HostResourceQueryOption] Clean up.
[server][HostResourceQueryOption] Show more information on the assertion.
[server][HostResourceQueryOption] Clean up so that a caller can omit to specify the table name.
[server][HostResourceQueryOption] Remove a method: setServerIdColumnName() that is no longer used.
[server][HostResourceQueryOption] Remove a method: setHostGroupIdColumnName() that is no longer used.