Split VSIX into Dev16 and Dev17

[DefaultRyan]

This splits the current VSIX into Dev16 and Dev17 flavors, and updates the marketplace description to emphasize that this VSIX contains templates and the debug visualizer. There are two compelling reasons for this split:

1. Because the C++/WinRT VSIX is now included in Dev17 (VS2022), we want the ability to configure and update the two extensions differently. There are still some technical issues to be worked out with updating an in-box VS component with a marketplace VSIX. Lighting up this behavior for Dev17 will almost certainly require some changes to the VSIX that could affect Dev16.
2. We want to start localizing the C++/WinRT project templates. To the best of my knowledge, this will require us to include an actual assembly (DLL) in the VSIX. And since Dev17 introduced breaking API changes and moved to 64-bit, this will also require us to split the extension into Dev16 (VS2019) and Dev17 (VS2022) specific flavors. (Previously, this VSIX got away without splitting because it didn't have any code referencing the VS SDK).

[DefaultRyan]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[DefaultRyan]

/asp run

[sylveon]

#918 also introduced code, maybe this could be looked at again as part of the localization effort.