Add actual host architecture telemetry key

Right now we report `host.arch` as [`runtime.GOARCH`](https://github.com/Azure/azure-dev/blob/572e7f47ee17b3cc10d5eb2380f0ef5e4be54c15/cli/azd/internal/tracing/resource/resource.go#L28)... This indicates the architecture of the compiled binary but not the actual architecture of the host.

To that end, we should see if we can report the actual architecture of the host (even when running in Rosetta 2).

This would give us a better idea of the number of people running `azd` on ARM64 machines even if they're running the x86_64 binary.