[Tizen] Verification name of a widget entry file

This patch contains function which verify name
of the widget entry file during installation.
Table contains list of proper names of the files
has been moved to constans.

BUG=XWALK-2983
'static' is missed, also the function is better to return const reference (off course there is a likelihood that the current solution is already optimized by compiler so that copying on return is obviated but it needs checking)