Fix Bug 2339:Responsiveness issue in UI if name(NSD/VNFD/VIM) is too long

	-Added the horizonal scroll in the dropdown of ng-select

Change-Id: I1119e439c7c4c82f93b6da9be29b9212bba8c7b7
Signed-off-by: SANDHYA.JS <sandhya.j@tataelxsi.co.in>
(cherry picked from commit 29c52a9b)