* Add track_event callback to execute_write_fn and write_wrapper
Allows write functions and write_wrapper generators to queue events
during a write operation that are dispatched after successful commit.
The fn or wrapper can optionally accept a `track_event` parameter
(detected via call_with_supported_arguments). Events are discarded
if the write raises an exception.
Does not yet handle the block=False (non-blocking) case - events
queued during non-blocking writes are currently silently discarded.
Refs https://github.com/simonw/datasette/issues/2681
* Dispatch track_event events for non-blocking (block=False) writes
Spawns a background asyncio task that awaits the write thread's reply
queue and dispatches pending events after a successful non-blocking
write. Events are still discarded if the write raises an exception.
Refs https://github.com/simonw/datasette/issues/2681
* Warn that events won't fire for other processes
Refs https://github.com/simonw/datasette/issues/2681#issuecomment-4157118662
