[Progress on Feature] Export Chat to zip

This is a note about the progress on the current plan of implementing Exporting Chats to an universal format for use for archival or as proof of something.
This is just meant as a todo-list/issue and not as an open feature discussion, if you want to propose an better idea please do so in a new or existing Feature Proposal topic.
You may post small improvement ideas here as long as they don’t blow up the scope like “re-importing the exported chat”.

The current idea is just to have something little more than the barebone text, irc-like thing that whatsapp has, so more in the direction of telegrams html exporter.

Current PR

-> https://github.com/deltachat/deltachat-core-rust/pull/1601
Left todo:

  • error handling (get rid of most unwrap)
  • ffi interface
  • json scheme that describes chat.json
  • test if files are there in archive (python?)

TODO

  • Export Locations
    • KML
    • GeoJSON
  • HTML Viewer
  • More Advanced Testing
    • Check validity and document json files with json schema
  • Report a progress like backup export (mainly write to zip step)