Id in <tizen:app-widget> element should begin with <TIZEN_APPLICATION_ID>

Id in <tizen:app-widget> element should begin with <TIZEN_APPLICATION_ID>

[Issue#]   WGL-573
[Problem]  Valid Id of <tizen:app-widget> element should be in format of
           <TIZEN_APPLICATION_ID>.<STRING>
[Cause]    Missing proper routine to check this condition.
[Solution] Add routine to check app-widget id.

[Verification]
    * Install widget attached to issue, which should fail:
      https://bugs.tizendev.org/jira/browse/WGL-573
    * Install correct widget, which should pass:
      https://bugs.tizendev.org/jira/browse/WGL-574

Change-Id: I07c408f192aab083cd0513e73bc35ffab7ed870d