Send & handle `JobUpdate.refresh_tasks = true` when many tasks are
updated simultaneously. This applies to things like cancelling &
requeueing an entire job.
This partially rolls back 67bf77de13d99b1bc5d7344951068822c4fadd88, as
it was too slow when 1000+ tasks were being updated all at once.
Check for jobs in 'cancel-requested' or 'requeued' statuses, and ensure
they transition to the right status. This happens at startup, before
even starting the web interface, so that a consistent state is presented.
When the job status changes, it impacts the task statuses as well. These
status changes are now no longer done with a single database query, but
instead each affected task is fetched, changed, and saved. This unifies
the regular & mass updates to the tasks, and causes the resulting task
changes to be broadcast to SocketIO clients.
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.
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.
Direct copy of the Flamenco Server Python code, for handling the change
of a job's status to trigger status changes on its tasks.
Not yet connected to the rest of the Manager logic.
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.
