* persist queued worker tasks to database on shutdown, fill worker queues from database on startup
* ensure the tasks are sorted by creation time before pushing them
* add migration to insert WorkerTask{} into database, add test for worker task persistence
* add test for recovering worker queues from database
* quick tweak
* whoops we ended up with double cleaner job scheduling
* insert each task separately, because bun is throwing some reflection error??
* add specific checking of cancelled worker contexts
* add http request signing to deliveries recovered from database
* add test for outgoing public key ID being correctly set on delivery
* replace select with Queue.PopCtx()
* get rid of loop now we don't use it
* remove field now we don't use it
* ensure that signing func is set
* header values weren't being copied over 🤦
* use ptr for httpclient.Request in delivery
* move worker queue filling to later in server init process
* fix rebase issues
* make logging less shouty
* use slices.Delete() instead of copying / reslicing
* have database return tasks in ascending order instead of sorting them
* add a 1 minute timeout to persisting worker queues
* improved server shutdown with more precise shutdown of modules + deferring of ALL of it
* move delivery and workers into separate files
* add worker task model and Serialize() / Deserialize() methods for message types
* start adding message serialize / deserialize tests
* start adding test cases
* update body rewinding to rely on standard library mechanism of r.GetBody()
* remove request rewinding (http.Client{} should already handle this)
* standard library already handles rewinding
* improved code comment
* move the newPOST() function contents to prepare(), fits better with current API
* add Serialize() / Deserialize() implementations for Delivery{} type
* finish writing FromClientAPI sserialize / deserialize tests
* start adding FromFediAPI{} serialize / deserialize test cases
* fix FromFediAPI{} tests
* add tests for delivery message type
* fix repeat code
* missing license header
* use testrig status and accounts for marshal / unmarshaling tests
* add a specific test for checking account RSA keys are preserved
