feat: Tag newly installed VMs as 'new'

[ivoheck]

Description

Please include a summary of the changes along with any relevant motivation and context.

After downloading a VM, a button appears that takes the user directly to the VM manager page.
Newly downloaded VMs are temporarily marked with the label "new" when the manager page is opened for the first time. The label disappears on subsequent visits.

• Closes feat: add a "Run" option after an image finishes downloading #73

Type of change

• New feature (non-breaking change which adds functionality)

Checklist:

• I have performed a self-review of my code
• I have tested my code in common scenarios and confirmed there are no regressions
• I have added comments to my code, particularly in hard-to-understand sections
• I have updated and committed pubspec.yaml and pubspec.lock
  • flutter pub get

yq above is yq-go

[lj3954]

I would choose a different icon for new, that looks like it would be alerting the user of an error.

[ivoheck]

I would choose a different icon for new, that looks like it would be alerting the user of an error.

You're right – I changed the icon to a different one that should fit better.

[ivoheck]

The test-build-ppa-x64 job is failing — is this something I can fix myself, or is it unrelated to the changes in this PR?

[lj3954]

Appears to be an unrelated issue.