Migrate functions to app package (#5106)

* Refactor and move session logic into app package

* Refactor email functions into the app package

* Refactor password update into app package

* Migrate user functions to app package

* Move team functions into app package

* Migrate channel functions into app package

* Pass SiteURL through to app functions

* Update based on feedback

api/user_test.go

@@ -508,7 +508,7 @@ func TestGetUser(t *testing.T) {
 		t.Fatal("shouldn't have accss")
 	}
 
-	UpdateUserRoles(ruser.Data.(*model.User), model.ROLE_SYSTEM_ADMIN.Id)
+	app.UpdateUserRoles(ruser.Data.(*model.User).Id, model.ROLE_SYSTEM_ADMIN.Id)
 
 	Client.Login(user.Email, "passwd1")
 
@@ -1226,7 +1226,7 @@ func TestUserPermDelete(t *testing.T) {
 	c.RequestId = model.NewId()
 	c.IpAddress = "test"
 
-	err := PermanentDeleteUser(user1)
+	err := app.PermanentDeleteUser(user1)
 	if err != nil {
 		t.Fatal(err)
 	}