Improvements to import, export and serialize

[nickchomey]

Would you be open to a PR that brings the following functionality?

• serialize + inject support for Documents
• export and serialize cfg (including custom handler functions) for both Index and Document then import/inject either to existing index/document or auto create Index/Document from the cfg container in the export.
• add optional compression to export and decompression on import
• export to Blob rather than JSON

I've implemented most of it now with tests, but I'm sure it could benefit from your review - especially for some of the Document stuff

[ts-thomas]

Hi Nick, generally it sounds very interesting to add or improve those functionalities. Would be very helpful to have all this features in their own PR. Please share if you like 🙏

[nickchomey]

Great! I just submitted a few PRs based off of what I had done a few months ago, rebased onto master. I don't really recall what I did or why at this point, but the copilot summaries seem accurate. Hopefully you can easily make sense of it all. I'm happy to discuss and refine anything.