And define `send_message_timeout_cancellable` in rpc_protocol_impl.hh
using the newly introduced rpc_handler entry point
in seastar that accepts both timeout and cancellable params.
Note that the interface to the user still uses abort_source
while internally the funtion allocates a seastar::rpc::cancellable
object. It is possible to provide an interface that will accept
a rpc::cancellable& from the caller, but the existing messaging api
uses abort_source. Changing it may be considered in the future.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
0b97806771