Add round end Discord pings, discord webhook API (#19468)

Content.Server/Discord/WebhookData.cs

@@ -0,0 +1,42 @@
+using System.Text.Json.Serialization;
+
+namespace Content.Server.Discord;
+
+// https://discord.com/developers/docs/resources/webhook#webhook-object-webhook-structure
+public struct WebhookData
+{
+    [JsonPropertyName("id")]
+    public ulong Id { get; set; }
+
+    [JsonPropertyName("type")]
+    public int Type { get; set; }
+
+    [JsonPropertyName("guild_id")]
+    public ulong? GuildId { get; set; }
+
+    [JsonPropertyName("channel_id")]
+    public ulong? ChannelId { get; set; }
+
+    [JsonPropertyName("user")]
+    public WebhookUser? User { get; set; }
+
+    [JsonPropertyName("name")]
+    public string? Name { get; set; }
+
+    [JsonPropertyName("avatar")]
+    public string? Avatar { get; set; }
+
+    [JsonPropertyName("token")]
+    public string Token { get; set; }
+
+    [JsonPropertyName("application_id")]
+    public ulong? ApplicationId { get; set; }
+
+    [JsonPropertyName("url")]
+    public string? Url { get; set; }
+
+    public WebhookIdentifier ToIdentifier()
+    {
+        return new WebhookIdentifier(Id, Token);
+    }
+}