since we've dropped the thift support, the `client_type` is always
`cql`, there is no need to differentiate different clients anymore.
so, we change `make_client_key()` so that it only return the IP address
and port.
Refs #3811
Refs #18416
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Now the connection_notifier is all gone, only the client_data bits are left.
To keep it consistent -- rename the files.
Also, while at it, brush up the header dependencies and remove the not
really used constexprs for client states.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>