dotnet CDN tracking issue

We are making important changes to the dotnet CND, due to `azureedge.net` domains no longer being supported/available, per https://github.com/dotnet/core/issues/9671.

The following are the tasks we intend to take on with target timelines. All of this is expected to evolve as we learn more.

Phase 1 (January):

- https://github.com/dotnet/install-scripts/issues/559
- https://github.com/dotnet/arcade/pull/15365
- https://github.com/dotnet/install-scripts/issues/558
- https://github.com/dotnet/install-scripts/issues/563
- https://github.com/dotnet/core/issues/9673
- https://github.com/dotnet/core/issues/9669
- https://github.com/dotnet/core/issues/9682
- https://github.com/dotnet/core/issues/9683

Phase 2 (February-March):

- https://github.com/dotnet/core/issues/9675

Phase 3 (April?):

- https://github.com/dotnet/core/issues/9676

Related:

- https://github.com/dotnet/core/issues/9677
- https://github.com/actions/setup-dotnet/issues/570