Azure support needed

[major]

I'm working on building Fedora images for Azure as part of BZ 2203192.

Azure has some strict requirements for a fixed VHD. Also, the VHD must be a whole number in megabytes.

The existing HyperV code in the repo comes up a bit short for Azure. Azure has some extra steps as noted in their documentation.

1. Image must be converted to raw
2. Final size is calculated via a bash script
3. The raw image is resized to that size
4. Correctly sized raw image is converted to a fixed size VHD

I'd be glad to do some tests and make a PR for the repo to add these to the existing HyperV code, but I'm not sure if we should make a separate bit of code for Azure here. Let me know how I should proceed and I'll be happy to help.