[Tizen] Further implementation of Blink-based orientation code

The ApplicationTizen class is now inherited from 'content::ScreenOrientationProvider'
since both Application and ScreenOrientationDispatcherHost correspond to a single
renderer process.
Also ScreenOrientationProvider initialization code is added to ApplicationTizen::Launch
method.
Merge pull request #2024 from pozdnyakov/Make_App_ScreenOrientationProvider

[Tizen] Further implementation of Blink-based orientation code