bugfix(z-index): Fixed several z-index problems, progress-bar inside nya deltagare is now hidden behind the header when scrolling. (TV-551)

Squashed commit of the following:

commit 87b53c3d03f71b5cfd6e632e39a3f2723deecdee
Author: Erik Tiekstra <erik.tiekstra@arbetsformedlingen.se>
Date:   Thu Sep 16 10:57:12 2021 +0200

    Fixed issue with z-indexes

apps/mina-sidor-fa/src/app/shared/enums/loader-type.enum.ts

@@ -0,0 +1,4 @@
+export enum LoaderType {
+  FULL_SCREEN = 'fullscreen',
+  ABSOLUTE = 'absolute',
+}