fix(renderer): dynamic views can't be prepended

[edusperoni]

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• Tests for the changes are included.

What is the current behavior?

The angular renderer doesn't support adding views to the first position:

<StackLayout>
  <ng-container *ngIf="someBoolean">
    <Label text="I come first"></Label>
    <Label text="I come second" *ngIf="someOtherBoolean"></Label>
  </ng-container>
</StackLayout>

Result:

I come second
I come first

This is because the renderer treats not having a previous element as needing to append.

1. ViewContainer at position 0. StackLayout is empty, StackLayout now contains ViewContainer at 0
2. add ng-container before ViewContainer (no previous element). StackLayout now contains [VC,ng-container] (should be the other way around). Doubly linked list references are now broken.
3. add "I come first" before ng-container. [VC, "I come first", ng-container]
4. add "I come second" before ng-container. [VC, "I come second", "I came first", ng-container] (linked list is broken, so it wraps around from ng-container until "I came first")

What is the new behavior?

1. ViewContainer at position 0. StackLayout is empty, StackLayout now contains ViewContainer at 0
2. add ng-container before ViewContainer (no previous element). StackLayout now contains [ng-container,VC]
3. add "I come first" before ng-container. ["I come first", ng-container, VC]
4. add "I come second" before ng-container. ["I come first", "I came second", ng-container, VC]

Fixes/Implements/Closes #[Issue Number].