[IOT-1573] Account User search revised in device-to-cloud communication

[IOT-1573] Account User search revised in device-to-cloud communication

 - user search logic added in Account Server
   - GET /oic/account/search?uid=u0001;uid=u0002
       (to search users using multiple "OR" conditions)
   - GET /oic/account/search?name=mike,email=mike@aaa.com
       (to search users using multiple "AND" conditions)

patch #4 : unnecessary logs are removed

Change-Id: Ib7aa014434a41d8a5092780b3dfc8de688faa465
Signed-off-by: yeonghun.nam <yeonghun.nam@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/14459
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jee Hyeok Kim <jihyeok13.kim@samsung.com>