Exporting a costume with an error exports the "error" costume.

[Ascor8522]

Expected Behavior

When right-clicking an SVG costume with an error (showing the quesrtion mark on a grey background), the original (broken) SVG costume should be exported, even tho its preview is not available.

Actual Behavior

The "error" SVG costume (the one with a grey background and a back question mark) is exported.

In the Scratch Editor:

The exported costumed onpened in VSCode:

The original costume fecthed from the CDN during project download:

Steps to Reproduce

1. Create a project.
2. Export a falty SVG or wait for it to be corrupted by the Scratch server at some point.
3. Open the costume editor of the corrupted/broken costume.
4. Export the costume by right-clicking it.

Operating System and Browser

Scratch online.

[BryceLTaylor]

The issue described here is definitely a concern, but is really a symptom of a broader problem. I've opened a new issue to address the broader problem here: scratchfoundation/scratch-gui#6838. I'm going to close this issue since it should be addressed in the designs for the broader issue.