Add registry search for upgrade policy keys

[joeloff]

Description

Add registry search operations to SDK installer bundles. The search operation will check for a global and version specific registry key. The version specific key takes precedence when present.

This is related to a customer request and part of a larger change. This PR only includes infrastructure changes to support changes in the Windows installer bundles. The change depends on changes in Arcade (https://github.com/dotnet/arcade/pull/15047).

NB: This PR will not build until the Arcade change is merged and flowed to the SDK.

Unlike the runtime and desktop runtime, the SDK needs to explicitly pull in the additional source file.

Risk

Low, this change only adds detection for the key, nothing will currently act on its value.

Testing

Testing can be done once all the relevant Arcade/Wix changes are merged and have flowed through.