fix: add originalFilename to emitted asset to correct the mainfest.json

[riw]

• Quick Checklist

• [X] I have read the contributing guidelines
• [ ] I have written new tests, as applicable (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)
• [ ] I have added a changeset, if applicable

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...) currently, only the last version of several conversions of an image with the same name is noted in manifest.json. this change adds an entry for each image.

• What is the new behavior (if this is a feature change)?

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

• Other information: