Make RuntimeFrameworkVersion apply to targeting packs

Originally, we were not planning on updating and releasing new TargetingPacks with every release but that has become common practice. What this means is that when customers want to control the version they pin to with RuntimeFrameworkVersion or to work around limitations in our implicit versions (like with [current 7.0 SDKS targeting .net 6](https://developercommunity.visualstudio.com/t/17617--NETSDK1145-after-updating-to-/10701350)), customers may want the RFV to apply to Targeting packs as well.

Perhaps we should simplify the logic in the process of framework references and runtime packs to simplify the version of RFV to apply to all versions and not just some packs.