fix(list-view): try to unwrap component views

[edusperoni]

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
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• Tests for the changes are included.

What is the current behavior?

If using a component without a native layout wrapper (stacklayout/etc), {N}'s listview will wrap the component in a layout. Doing so will break change detection

What is the new behavior?

We try to unwrap the view to fetch the stored template key

Fixes #30.

[NathanWalker]

Published with 12.1.0-rc.5 - will be part of the official 12.1 release - we may jump to 12.2 to align with Angular's latest before taking latest main commits to release.