"
Streamed view updates parasitized on writing io priority, which is
reserved for user writes - it's now properly bound to streaming
write priority.
Verified manually by checking appropriate io metrics: scylla_io_queue_total_bytes{class="streaming_write" ...} vs scylla_io_queue_total_bytes{class="query" ...}
Tests: unit(dev)
"
Fixes#4615.
* 'assign_proper_io_priority_to_streaming_view_updates' of https://github.com/psarna/scylla:
db,view: wrap view update generation in stream scheduling group
database: assign proper io priority for streaming view updates
(cherry picked from commit 2c7435418a)