wsl --mount --vhd <volume>.vhdx --bare should report the device used to attach the volume

**Is your feature request related to a problem? Please describe.**
I would like to be able to script the creation of a WSL distro from bash and I can (from a WSL distro running from a PowerShell admin session) do:

```
powershell.exe New-VHD -Path /mnt/c/Users/mlwp/Storage/Projects3Dynamic.vhdx -SizeBytes 256GB -Dynamic -BlockSizeBytes 1MB
wsl.exe --mount --vhd Projects3Dynamic.vhdx --bare # attaches as /dev/sd? but does tell me which
mkfs.btrfs -f -L projects3 /dev/sdi
wsl --mount --vhd C:/Users/mlwp/Storage/Projects3Dynamic.vhdx --name projects3
```

**Describe the solution you'd like**
wsl.exe --mount should return device where volume is mounted

**Describe alternatives you've considered**
Not clear what if any other options I have for an automated script

**Additional context**
This is part of my attempt to script my workflows

Start by reproducing the documented bash and PowerShell sequence with `wsl.exe --mount --vhd ... --bare` and observe its current output. Trace the `--mount --vhd --bare` CLI entry point and define completion as reporting the device attached to the volume so the subsequent formatting command can use it without a hard-coded `/dev/sd?` path.

Written by the indexing model from the issue text.