Add `fetchJobTasks` operation to the Jobs API. This returns a summary of
each of the job's tasks, suitable for display in a task list view.
The actually used fields may need tweaking once we actually have a task
list view, but at least the functionality is there.
To prepare for job status changes being requestable from the API, store
the reason for any status change on the job itself.
Not yet part of the API, just on the persistence layer.
SQLite can return `SQLITE_BUSY` errors when it's doing too many things at
the same time. This is now improved a bit by setting a 5-second timeout,
during which the SQLite driver will wait for the database to become
available. If that doesn't happen, Flamenco Manager will return a
`503 Service Unavailable` response so that the client knows to back off
a little.
- Addon switches between filesystem-packing and Shaman-packing
automatically, depending on whether the Manager has Shaman enabled.
- Actually using BAT for Shaman packing.
It doesn't work though, some error occurs when receiving Shaman response
from the Manager in the Addon.
This introduces some more conceptual changes to Shaman. The most important
one is that there is no longer a "checkout ID", but a "checkout path".
The Shaman client can request any subpath of the checkout directory,
so that it can handle things like project- or scene-specific prefixes.
The add-on code was copy-pasted from other addons and used the GPL v2
license, whereas by accident the LICENSE text file had the GNU "Affero" GPL
license v3 (instead of regular GPL v3).
This is now all streamlined, and all code is licensed as "GPL v3 or later".
Furthermore, the code comments just show a SPDX License Identifier
instead of an entire license block.
The task status change → job status change code is a direct port of the
Flamenco Server v2 code written in Python.
There is no job status change → task status changes logic yet, and the
tests are also far from complete.
