Added support for new property: output_style

[vanvught]

The DMX output can be delta or constant
The new JSON property is output_style_|port|

{
    "artnet.txt": {
        "long_name": "DMX4 Art-Net 4 https://gd32-dmx.org",
        "enable_rdm": 0,
        "failsafe": "hold",
        "universe_port_a": 1,
        "direction_port_a": "output",
        "label_port_a": "Port 1",
        "universe_port_b": 2,
        "direction_port_b": "output",
        "label_port_b": "Port 2",
        "universe_port_c": 3,
        "direction_port_c": "output",
        "label_port_c": "Port 3",
        "universe_port_d": 4,
        "direction_port_d": "output",
        "label_port_d": "Port 4",
        "merge_mode_port_a": "htp",
        "output_style_a": "const",
        "rdm_enable_port_a": 0,
        "merge_mode_port_b": "htp",
        "output_style_b": "delta",
        "rdm_enable_port_b": 0,
        "merge_mode_port_c": "htp",
        "output_style_c": "delta",
        "rdm_enable_port_c": 0,
        "merge_mode_port_d": "htp",
        "output_style_d": "delta",
        "rdm_enable_port_d": 0,
        "destination_ip_port_a": "192.168.2.255",
        "destination_ip_port_b": "192.168.2.255",
        "destination_ip_port_c": "192.168.2.255",
        "destination_ip_port_d": "192.168.2.255",
        "protocol_port_a": "artnet",
        "priority_port_a": 100,
        "protocol_port_b": "artnet",
        "priority_port_b": 100,
        "protocol_port_c": "artnet",
        "priority_port_c": 100,
        "protocol_port_d": "artnet"
    }
}