Escape " in JSON generation.

[rtibbles]

Summary

• Fixes a bug in ancestor JSON generation where any title with " in it would cause invalid JSON to be generated
• Escapes any textual " during JSON generation
• Adds test for regression

References

Fixes issue detailed here: #8570 (review)

Reviewer guidance

Rerun ancestor generation in kolibri shell:

from kolibri.core.content.upgrade import metadata_annotation_update
metadata_annotation_update()

Check that the error no longer occurs.

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Reviewer checklist

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[nucleogenesis]

I found nothing worthwhile that breaks this. Just things like " and """" (but not "" or """...)

The stuff I mentioned in #8570 works just fine.

LGTM!

[indirectlylit]

I don't have a specific test case to break this, but just flagging that doing this kind of search/replace may not always work. Is there any risk of a situation similar to this?

#5981