source-coda: add page content stream

[Yevhen Lazhyntsev (EugenLaz)]

Currently, the source-coda connector allows us to sync metadata about Pages (title, ID, creation date) via the Pages stream, but there is no stream available to retrieve the actual body content of those pages. For use cases involving search indexing, LLM context augmentation (RAG), or archiving, we need access to the page content itself.

To support such use case I propose to add new stream:
Stream Name: page_content

Source: Coda API (utilizing GET /docs/{docId}/pages/{pageId}/content)

Primary Key: pageId

Sync Logic: This will be a child stream or require iterating through the list of pages retrieved from the parent Doc.

Additional considerations: stream returning content as single objects, vs each line being a separate item -> because native coda API does not provide reference to page in response object, we need to have href in the response in order to parse it.
Having whole object in schema allows us to achive that

[Yevhen Lazhyntsev (EugenLaz)]

#72530
Pr made by me