feat: vectors have attribution to users and groups

[mkozakov]

In my organization we use google docs. Each doc has it's set of permissions and groups that it is shared with. As an admin I want to export all of the organization's google docs into Casibase, and make sure that casibase users can only query vectors that come from files they have access permissions for (public files, files they created, files that were shared with them directly or with a group they are part of).

This ticket is not specific to google docs.