[Stride CLI] `Stride.Templates.AssetPacks` templates not usable through `stride new`

[ferafiks]

Release Type: beta

Version: 4.4.0-beta5

Platform(s): all

Describe the bug
Running stride new stride-pack-building-blocks can't detect the template. This is because the asset packs package isn't a dependency of Game Studio, thus isn't downloaded. Running dotnet new install Stride.Templates.AssetPacks does not fix the problem, because the templates aren't installed to the nuget cache (~/.nuget/packages), but the template cache (~/.templateengine/packages).

There are 3 solutions to this:

1. Make Stride.Templates.AssetPacks a dependency of Stride.GameStudio just like every other template package.
2. Automatically download Stride.Templates.AssetPacks to the cache when downloading stride.
3. Try fetching Stride.Templates.AssetPacks (and probably other template packages that are missing) from nuget.org when running stride new.

To Reproduce
Steps to reproduce the behavior:

1. Download Stride CLI
2. Run stride new list and notice that Stride.Templates.AssetPacks isn't showing up.

Expected behavior
You can add an asset pack to a project through the stride command.