[enhancement]: Add Chinese translation from Ernie to metadata

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Contact Details

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### What should this feature add?

When used with "prompt enhancement" switched on, the ERNIE model produces an elaborated, extended restatement of the prompt—in Chinese. And that is the prompt that is actually used. Since that's really the prompt that's being used, it seems to me it should be retrievable or available in the metadata *somewhere*. Like, "enhanced_prompt" or something. Just a thought. Should be straightforward enough to route the output of the enhancement node to add it as a non-standard metadata element?

### Alternatives

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### Additional Content

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