Processing watch application from config.xml

Processing watch application from config.xml

Writes information about wgt's watch application to manifest_x
and adds it to generated platform xml in wgt-backend.

In tizen 2.x watch-application was not registered by wgt-installer
AT ALL. This was done libwatch-application.so pkgmgr plugin parser.
This behaviour should be probably removed so that only app-installer
insert data into pkgmgr database. After this commit data of all
applications (including watch-application) is added to pkgmgr_parser.db.

Note that update installation of watch-application will work only
when tizen-manifest.xml parsing changes will be introduced.

Requires:
 - https://review.tizen.org/gerrit/#/c/60241/

Change-Id: I67f9cf1c04ecf435cfc90f5ab83d2ccebbc45a4a