Use launch_activate_socket in plist

[liudongmiao]

Is your feature request related to a problem? Please describe.
Use launch_activate_socket for dynamic socket in macos.

Describe the solution you'd like

        <key>Sockets</key>
        <dict>
                <key>listen_key</key>
                <dict>
                        <key>SockNodeName</key>
                        <string>0.0.0.0</string>
                        <key>SockServiceName</key>
                        <string>listen_port</string>
                        <key>SockType</key>
                        <string>stream</string>
                </dict>
        </dict>

Describe alternatives you've considered
None.

Additional context
None

shadowsocks-libev support this features since 2.6.0, in commit shadowsocks/shadowsocks-libev@d2b7e67, and use a magic listener name Listeners (pr by me :)

shadowsocks-rust support this features since latest 1.18.2, previous is buggy before shadowsocks/shadowsocks-rust@dcdeca0, use TCPListener in locals[0], and you can wait for next version to use it in outer config since shadowsocks/shadowsocks-rust@7b4a0a1 (pr by me :)