This refactor was born out of the inter-dependency cycles developing
between the "background" module and just about every other module which
was caused by the background module becoming a dependency of every
module that needed to background work and the fact that the background
module was also supposedly responsible for the logic for processing
those tasks.
Instead the "background" module is now very, very shallow and relies
entirely on the Postgres NOTIFY logic for triggering jobs. There's a new
table, `job` which holds just a type and single row ID.
All told, this means that jobs can be added to the queue as part of the
API-level or platform-level transaction, ensuring atomicity, and
processing coordination is handled by the platform module, which can
depend on anything.
The goal of this rework is to make it so I can pass around platform.User
instead of a pair of models.Organization and models.User. This is useful
for reason I kind of forget now, but it started with working on
notifications and ballooned massively from there into refactoring a
number of things that were bugging me.
This also includes a tiny amount of work on server-side events (SSE).
* background stuff lives inside the platform now, which I need for
having it push updates through SSE
* userfile now lives in the platform, under file, so other platform
functions can safely use it
* oauth is broken into pieces and inside platform because other stuff
was calling it already, but badly.
* notifications go into the platform as well
