Ensure vm is finished booting before connecting to it via terminal

[edlerd]

Done

• Ensure vm is finished booting before connecting to it via terminal

Fixes #1063

QA

1. Run the LXD-UI:
   • On the demo server via the link posted by @webteam-app below. This is only available for PRs created by collaborators of the repo. Ask @mas-who or @edlerd for access.
   • With a local copy of this branch, build and run as described in the docs.
2. Perform the following QA steps:
   • start / stop vms and from the instance terminal page.

[webteam-app]

Demo

Jenkins

demos.haus

[Kxiru]

Looks good to me! :) Might wait for another perspective, also!

[mas-who]

I think we should change the empty state text for the state where the instance is booting. Maybe "Instance starting" for the heading and "Terminal will be ready once the instance booting is complete." for the message?

[mas-who]

LGTM 👍 thanks for the fix!