Early look at the LXD web UI

Something that's been requested since the beginning of the LXD project, but we finally have it, a built-in LXD web interface. Let's take a look and see what it can do today and talk a bit about where it's headed.

RESOURCES:
- LXD UI: https://github.com/canonical/lxd-ui
- Github: https://github.com/canonical/lxd
- Website: https://ubuntu.com/lxd
- Community forum: https://discourse.ubuntu.com/c/lxd/