Version-agnostic App component

[guardrex]

Fixes #23696

Thanks @johndhunter! 🚀 ... This will be the best way to go for now. I'll revisit when I reach the security node on UE passes in 2022 and perhaps make it so that versioned code is loaded. The problem with doing that now is that:

• It's a change that will require similar work in other areas. I might even decide in the end to use this "see the ref source" approach for everything. The framework churn is challenging to keep up with, and that's a guaranteed winner for churn as long as the dev selects the right release in the PU repo (per the INCLUDE here).
• Or, we might be dropping this coverage entirely in 2022 in favor of the Azure docs coverage. If so, then we don't want to spend a lot of time making changes to this at this time. That's a waste of ⏱️ ... thus a waste of 💰 ... if it comes to pass that all of this gets dropped here.