class Server

Called when a search this client added finds a matching service on a peer.

`peer_id` is the peer the service was found on.

`protocol` includes the ProtocolDescriptorList in the service record if it exists

(it is also included in `attributes`.)

`attributes` contains all attributes requested from the search that are present on the

peer record. It may also include additional attributes.

Each ServiceFound call should be acknowledged by replying.

A limited amount of unacknowledged results will be sent on the channel. Results may be

dropped if results are received while too many results are unacknowledged.

|bind_handler| returns a handler that binds incoming connections to this

server implementation.

The returned handler borrows the server instance.

The server must outlive the provided |dispatcher|. Only after

the dispatcher is shutdown will it be safe to destroy the servers.

The server should not be moved.