Enable configuring local address and range of ports for client sockets to be bound to

[wprzytula]

Motivation

Cpp driver exposes the following functions. Their docstrings contain motivation for both.

/**
 * Sets the local address to bind when connecting to the cluster,
 * if desired.
 *
 * @public @memberof CassCluster
 *
 * @param[in] cluster
 * @param[in] name IP address to bind, or empty string for no binding.
 * Only numeric addresses are supported; no resolution is done.
 * @return CASS_OK if successful, otherwise an error occurred.
 */
CASS_EXPORT CassError
cass_cluster_set_local_address(CassCluster* cluster,
                               const char* name);
/**
 * Sets the range of outgoing port numbers (ephemeral ports) to be
 * used when establishing the shard-aware connections. This is
 * applicable when the routing of connection to shard is based on
 * the client-side port number.
 * 
 * When application connects to multiple CassCluster-s it is advised
 * to assign mutually non-overlapping port intervals to each. It is assumed
 * that the supplied range is allowed by the OS (e.g. it fits inside
 * /proc/sys/net/ipv4/ip_local_port_range on *nix systems)
 *
 * @public @memberof CassCluster
 *
 * @param[in] cluster
 * @param[in] lo The lower bound (inclusive)
 * @param[in] hi The upper bound (exclusive)
 * @return CASS_OK if successful, otherwise the range is invalid.
 */
CassError cass_cluster_set_local_port_range(CassCluster* cluster,
                                            int lo,
                                            int hi);

Implementing them both make sense for Rust driver itself, as well as to support them in cpp-rust-driver.

Solution

Add the following methods to SessionBuilder (and corresponding config to SessionConfig, and respect it codewide):

fn driver_bind_address(self, addr: SocketAddr) -> Self;

fn driver_bind_port_range(self, port_range: Range<u16>) -> Self;