feat: ability to use retrosocket without pairing

[jiraguha]

Signed-off-by: jpiraguha [email protected]

Hey @joshlong,

What if the RSocketClientFactoryBean could create a requester directly without pairing? The drawback is that we will need to provide on client config statically in @RSocketClient annotation but it would be closer to Feign experience!

ex:

@RSocketClient(host = "${greeting-client.host:localhost}", port = "${greeting-client.port:8888}", mode = MANAGED)