Fix Bug 2292: Invalid Member VNF index in Manual Scaling after NS Update remove operation

	- Will get member vnf index value from vnfinstances api instead
	  of nsinstances api in manual scaling.
	- Also made code refactoring in other components to avoid linting issue

Change-Id: I30de65c6fe23ddbf560ab45a8505759c4adb5978
Signed-off-by: SANDHYA.JS <sandhya.j@tataelxsi.co.in>