DStack as a Data Service

[PicoCreator]

This maybe implemented across multiple projects, but the overall is being documented

• Support for jsql_legacy within dstack, this helps older application migrate to the new data layer.

The following downwards maybe branched out to a separate project.

• dstack-data-service is a configurable API backend, for all dstack data.
  - [ ] Data services can be added for specific DataObjectMap, KeyValueMap, etc
  - [ ] Data services should support type checking (optional, maybe?)
  - [ ] Data service should support a graphQL endpoint
• use of security / data filter profile (managed by the API consumer)
  - [ ] Data services can be done, with provided profiles.
• option to add-on API modules
  - [ ] Honestly, this is only for the login service
• Security housekeeping stuff
  - [ ] Support simple user/pass auth for connections