Multi user features :

->Use Usr App related fonctions instead of Global App related Functions

Signed-off-by: Sabera Djelti (sdi2) <sabera.djelti@open.eurogiciel.org>
I haven't looked into pkgmgr code yet, but I guess if the logic in `pkgmgrinfo_appinfo_get_usr_appinfo` and `pkgmgrinfo_appinfo_get_appinfo` are similar, they can be merged into one func, which will check if `uid`==0. It is a common behavior in Posix functions.