[BUG] WAC will not allow subfolder to store VM images on Single-Node Hyper-V host

**Describe the bug**
When trying to specify a folder for VM images, WAC only presents a dropdown with the top-most drive letters as options. You cannot specify a subfolder (ex - `D:\ErnieAKSTest`) and instead have to shove everything into the root of the drive.

**To Reproduce**
1. Try to setup a management cluster on single-node HV host
2. Get to step 4 (HOST CONFIGURATION)
3. Click the second drop down and smash your face into desk

**Expected behavior**
The ability to specify an exact folder without using Powershell.

**Screenshots**


**Environment:**
- Browser: Chrome
- Version: 104.0.5112.102
- WAC Version: 2110.2 (build 1.3.2204.19002)
- AKS-HCI Extension Version: 2.79.0
- AKS-HCI Version: n/a
- Kubernetes Version: n/a