[Tizen] xwalk should get the installed apps list from AIL

Xwalk should get the installed apps list from AIL (it is possible
since 1e4f86873d11f685169e6bce886fceced59f20ce).

Before this change xwalk used pkgmng which was wrong as a package
and an app are the different things and using both AIL and pkgmng
storages at the same time could lead to data inconsistency.
Merge pull request #2254 from pozdnyakov/Use_AIL_to_list_apps

[Tizen] xwalk should get the installed apps list from AIL
[Tizen][Runtime] Sort out the logic of app id.

The patch of app id I made some days ago make the logic of app
id become too complex, so I sort out the logic of app id:
For xpk, [app_id] = GenerateId or GenerateIdForPath,
             [tizen_app_id] = xwalk.[app_id]
For wgt, [app_id] = GenerateId([tizen_app_id])
             [tizen_app_id] = Get from config.xml

Beside since we start get app info from ail, we can only get app
data from storage with [tizen_app_id].