feat: add refer option to export conversation.json using API

[moonmd]

When there are too many conversations, the Export All fails. This feature allows batch export of conversations with pictures using the official export provided by OpenAI. The limit is still currently around 300 due to the inevitable server errors.

[pionxzh]

Sorry, I don't quite understand what this "Refer" actually does. Can you explain more?

It seems this PR simply adds an option to choose. But there is no difference on the behavior.

[moonmd]

It downloads the entries in conversations.json again using the API instead of using the contents of the json.
The reason I added the option is because fetchAllConversations fails before gathering all 1400+ conversations from my history.
I can then select the conversations and export them with pictures.

[moonmd]

The functional difference occurs in

const exportAll = useMemo(() => {
    return exportSource !== 'Local' ? exportAllFromApi : exportAllFromLocal
}, [exportSource, exportAllFromApi, exportAllFromLocal])

because of the additional ExportSource:

type ExportSource = 'API' | 'Local' | 'Refer'

[pionxzh]

Can you rebase and remove the modification to dist/*? bundled js are automatically generated by the CI.
I will test tomorrow. Thanks. 🙏

[moonmd]

Continued in #271