[WRTjs][VD] Get add-on info in local manifest file

[WRTjs][VD] Get add-on info in local manifest file

Now app direct launch performance, get add-on using pkgmgr api, it cost
some time(depend on installed app count), so TV plan to optimize this logic,
when add-on is installed, vd-wgt-backend save mainifest.json to '/home/
owner/apps_rw/xwalk-service/addon/tizenid(***.***)/', then web app directly
launch or wrt-loader launch, we can get add-on info from these mainfest
files directly, it will only cost little time.

Change-Id: If1ee7fc1777220dd9f6ff8af3d5c007c2c24441c
Signed-off-by: liwei <wei90727.li@samsung.com>