feat!(sdbapi): restructure, expand user details

feat(sdbapi): new error handling

feat(sdbapi): endpoint for joining games

feat(sdbapi): endpoint for getting own games

feat(sdbapi): helper for getting user by email

WIP(sdbapi): migrate game table

Basic API with register and login (#1)

Reviewed-on: https://src.quest/skye/deck-builder/pulls/1