Enable-ExperimentalFeature does not work on Azure

`Enable-ExperimentalFeature` fails with the "access denied" error. As a result, Azure Functions users cannot enable experimental PowerShell features.

Apparently, `Enable-ExperimentalFeature` needs write access to the `$env:HOME` directory, and this path is mounted as read-only (at least on Consumption). In order to fix this, we need to either make `$env:HOME` point to a writable location (such as D:\home\data) or allow passing a different location to the PowerShell SDK.