Web-based WP-CLI terminal

It would be great to have a WP-CLI terminal in the portal so people who aren’t at their primary dev computer or aren’t super comfortable with SSH can dip their toes into WP-CLI in a less intimidating way. This would probably help as a stepping stone towards getting people to accept the use of WP-CLI instead of a GUI for many common tasks. We could even provide some copy-pasteable commands for common tasks. Something like this might lower the barrier of entry just enough that we could put off or avoid building GUIs for many common tasks.