Add "probe" method to check if client is still connected to the server

[jtnelson]

• Add probe method to Concourse client
• Add probe method to the ConnectionPool that pulls a random connection and tests whether it is still connected
• Implementation in 0.11 can call inventory() to see if the connection is still alive
• In 0.12 add a thrift method called probe that returns true
• In the client catch an exception for a broken pipe or inability to write and return false
• Consider adding a reconnect() method that can be used to reestablish the connection if the probe fails

/**
 * Probes the current connection to the server.
 * <p>
 * This method checks if the client is still connected to the server by sending a query or signal
 * and awaiting a response. It is used to ensure the client's ability to communicate with the server
 * remains intact.
 * 
 * @return boolean - {@code true} if the client is currently connected to the server,
 *                   {@code false} otherwise.
 */
public boolean probe() {
    // implementation code here
}