Add ddev-live pull support to ddev

[rfay]

Is your feature request related to a problem? Please describe.

ddev-live can now be supported by ddev, Yay!

Describe the solution you'd like

• Bundle the ddev-live client into the web image
• Provide an auth technique
• Use ddev-live pull to pull what we need.

This is based on how we do pantheon.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.