The `view_update_write_response_handler` class, which is a subclass of
`abstract_write_response_handler`, was created for a single purpose:
to make it possible to cancel a handler for a view update write,
which means we stop waiting for a response to the write, timing out
the handler immediately. This was done to solve issue with node
shutdown hanging because it was waiting for a view update to finish;
view updates were configured with 5 minute timeout. See #3966, #4028.
Now we're having a similar problem with hint updates causing shutdown
to hang in tests (#8079).
`view_update_write_response_handler` implements cancelling by adding
itself to an intrusive list which we then iterate over to timeout each
handler when we shutdown or when gossiper notifies `storage_proxy`
that a node is down.
To make it possible to reuse this algorithm for other handlers, move
the functionality into `abstract_write_response_handler`. We inherit
from `bi::list_base_hook` so it introduces small memory overhead to
each write handler (2 pointers) which was only present for view update
handlers before. But those handlers are already quite large, the
overhead is small compared to their size.
Use this new functionality to also cancel hint write handlers when we
shutdown. This fixes#8079.
Closes#14047
* github.com:scylladb/scylladb:
test: reproducer for hints manager shutdown hang
test: pylib: ScyllaCluster: generalize config type for `server_add`
test: pylib: scylla_cluster: add explicit timeout for graceful server stop
service: storage_proxy: make hint write handlers cancellable
service: storage_proxy: rename `view_update_handlers_list`
service: storage_proxy: make it possible to cancel all write handler types
ffce6d94fc