server: add synchronization of ping/pong mechanism

[niklasad1]

Currently jsonrpsee doesn't synchronize ping/pong instead it assumes that a pong should be seen at the configured interval however if the server is really busy like handling plenty of concurrent connections/messages.

Then it's possible that send operation takes longer than configured interval and that peer is regarded as inactive.

Thus, we should modify the current implementation such that jsonrpsee measures the time from that the ping is send until the pong received (associate each ping with pong)