Fix image filter on instance selection

[edlerd]

Done

• Fix image filter on instance selection
• Ubuntu images would not be filtered when selecting other distributions because of invalid row keys

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 instance creation, select image modal
   • filter by distribution
   • ensure no errors in console and rows represent filter status

[webteam-app]

Demo

Jenkins

demos.haus

[mas-who]

LGTM thanks for the fix 👍