Deploy WSL with a regular user account

[kousu]

This matches the result you get when you deploy it interactively: when you run wsl you get the $ prompt. Before, running wsl would get you a # prompt, which may or may not have negative consequences on a dev machine.

The only difference from install distros from the Microsoft Store is that we set the sudo password for you.

Fixes #90.

[ghost]

All CLA requirements met.

[kousu]

This is a little awkward because each distro has three unique IDs:

• the link (e.g. https://aka.ms/wsl-ubuntu-1804, https://aka.ms/wsl-debian-gnulinux)
• the name used by WSL itself to key on each distro (e.g. "Ubuntu-18.04", "Debian")
• the name of the DistroLauncher.exe (e.g. "ubuntu1804.exe", "debian.exe")

If you have ways to fix this up please suggest them.