Add support for `gif` stickers

DiscordChatExporter.Core/Discord/Data/Sticker.cs

@@ -7,7 +7,12 @@ using JsonExtensions.Reading;
 namespace DiscordChatExporter.Core.Discord.Data;
 
 // https://discord.com/developers/docs/resources/sticker#sticker-resource
-public record Sticker(Snowflake Id, string Name, StickerFormat Format, string SourceUrl)
+public partial record Sticker(Snowflake Id, string Name, StickerFormat Format, string SourceUrl)
+{
+    public bool IsImage => Format != StickerFormat.Lottie;
+}
+
+public partial record Sticker
 {
     public static Sticker Parse(JsonElement json)
     {
@@ -22,6 +27,7 @@ public record Sticker(Snowflake Id, string Name, StickerFormat Format, string So
                 StickerFormat.Png => "png",
                 StickerFormat.Apng => "png",
                 StickerFormat.Lottie => "json",
+                StickerFormat.Gif => "gif",
                 _ => throw new InvalidOperationException($"Unknown sticker format '{format}'.")
             }
         );

DiscordChatExporter.Core/Discord/Data/StickerFormat.cs

@@ -4,5 +4,6 @@ public enum StickerFormat
 {
     Png = 1,
     Apng = 2,
-    Lottie = 3
+    Lottie = 3,
+    Gif = 4
 }

DiscordChatExporter.Core/Exporting/MessageGroupTemplate.cshtml

@@ -634,7 +634,7 @@
                     @foreach (var sticker in message.Stickers)
                     {
                         <div class="chatlog__sticker" title="@sticker.Name">
-                            @if (sticker.Format is StickerFormat.Png or StickerFormat.Apng)
+                            @if (sticker.IsImage)
                             {
                                 <img class="chatlog__sticker--media" src="@await ResolveAssetUrlAsync(sticker.SourceUrl)" alt="Sticker">
                             }