Check PDM Initialization before excuting exposed PDM APIs

Check PDM Initialization before excuting exposed PDM APIs
- There is a case that user might call PDM API without initialization.
  This patch could prevent this case by checking initialized status of sqlite DB.

[Patch  #2] Removing Tab

Change-Id: Iaa9aa0f8f04fa8e69ab79c90fb5fc6ee6bbfd3b3
Signed-off-by: Woochul Shim <woochul.shim@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/2424
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Ashwini  Kumar <k.ashwini@samsung.com>
Reviewed-by: Sachin Agrawal <sachin.agrawal@intel.com>