[MM bugfix] Put model install errors on the event bus

[lstein]

Summary

Model install errors were not being placed on the event bus, preventing the web interface's Model Install tab from reporting errors. This would cause the model install status to be shown as "pending" and never update.

This applies a small fix to the issue, and adds a new unit test for regressions.

Related Issues / Discussions

As far as I can see, nobody has reported this.

QA Instructions

1. Launch the web interface
2. Go to the model manager panel
3. Click "Add Model" and URL or local path
4. Enter a bad URL (e.g. one that doesn't point to a model)
5. The model install queue should immediately show a new entry with status Failed

Merge Plan

Merge when approved.

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Tests added / updated (if applicable)
• Documentation added / updated (if applicable)

[psychedelicious]

Thanks, I've been wondering why the errors weren't showing up! I had only tested with civitai, but with the api tokens thing not working, I just assumed it was a civitai issue.

[lstein]

Thanks, I've been wondering why the errors weren't showing up! I had only tested with civitai, but with the api tokens thing not working, I just assumed it was a civitai issue.

Yes, I thought it was a Civitai problem as well because wget wasn't working as it used to from the command line. However, this turned out to be an unrelated problem involving Civitai->Cloud Flair redirects.