Add ability to use the steam API as an alternative for Valve Master Server queries.

[CosminPerRam]

What is this feature about?
Add the possibility to use the steam API for the valve master server queries, this might or might not fix #106.

Additional context/references
On the documentation page for querying the Valve master server, there is a short description for querying the steam API as an alternative, but seems to be undocumented.

[cainthebest]

i looked into this and i think it looks good, i was able to get this response from the steam api. it does need a api key but all you need is 1 game on a steam account to gen a key from https://steamcommunity.com/dev/apikey. when testing i just used "test" as the domain and it worked fine. still unsure on the filter field though here https://steamapi.xpaw.me/#IGameServersService/GetServerList.

Will re prioritize this as a v1 service

{
    "response": {
        "servers": [
            {
                "addr": "169.254.109.52:24712",
                "gameport": 24712,
                "steamid": "90208014253273118",
                "name": "(5)'s Server",
                "appid": 10,
                "gamedir": "cstrike",
                "version": "1.1.2.7/Stdio",
                "product": "cstrike",
                "region": -1,
                "players": 2,
                "max_players": 2,
                "bots": 0,
                "map": "cs_mansion",
                "secure": true,
                "dedicated": false,
                "os": "w"
            },
            {
                "addr": "169.254.136.14:27704",
                "gameport": 27704,
                "steamid": "90208014778927126",
                "name": "iOS-Andrei's Server",
                "appid": 10,
                "gamedir": "cstrike",
                "version": "1.1.2.7/Stdio",
                "product": "cstrike",
                "region": -1,
                "players": 5,
                "max_players": 32,
                "bots": 0,
                "map": "cs_assault",
                "secure": true,
                "dedicated": false,
                "os": "w"
            },
            {
                "addr": "169.254.186.27:7456",
                "gameport": 7456,
                "steamid": "90208015003881495",
                "name": "oapinilla's Server",
                "appid": 10,
                "gamedir": "cstrike",
                "version": "1.1.2.7/Stdio",
                "product": "cstrike",
                "region": -1,
                "players": 1,
                "max_players": 32,
                "bots": 30,
                "map": "de_vertigo",
                "secure": true,
                "dedicated": false,
                "os": "w"
            }
           // .... very long
        ]
    }
}

[cainthebest]

found a post on stack on how someone was filtering the ip, i would assume filtering other props follow the same structure.

https://stackoverflow.com/questions/71612241/steam-api-how-to-query-a-server-to-get-server-info-not-using-a2s

php example:

    $url = "https://api.steampowered.com/IGameServersService/GetServerList/v1/?key=API_KEY&filter=addr\185.254.99.6:27015";
    $json = file_get_contents($url);
    $table2 = json_decode($json, true);
    $table = $table2["response"]["servers"][0];
    $mapname = $table['map'];