More parsing leniency

Closes #767

DiscordChatExporter.Core/Discord/Data/Attachment.cs

@@ -36,7 +36,7 @@ public partial record Attachment
         var url = json.GetProperty("url").GetNonWhiteSpaceString();
         var width = json.GetPropertyOrNull("width")?.GetInt32OrNull();
         var height = json.GetPropertyOrNull("height")?.GetInt32OrNull();
-        var fileName = json.GetProperty("filename").GetNonWhiteSpaceString();
+        var fileName = json.GetProperty("filename").GetNonNullString();
         var fileSize = json.GetProperty("size").GetInt64().Pipe(FileSize.FromBytes);
 
         return new Attachment(id, url, fileName, width, height, fileSize);

DiscordChatExporter.Core/Discord/Data/Guild.cs

@@ -23,7 +23,7 @@ public record Guild(Snowflake Id, string Name, string IconUrl) : IHasId
     public static Guild Parse(JsonElement json)
     {
         var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
-        var name = json.GetProperty("name").GetNonWhiteSpaceString();
+        var name = json.GetProperty("name").GetNonNullString();
         var iconHash = json.GetPropertyOrNull("icon")?.GetNonWhiteSpaceStringOrNull();
 
         var iconUrl = !string.IsNullOrWhiteSpace(iconHash)

DiscordChatExporter.Core/Discord/Data/Role.cs

@@ -12,7 +12,7 @@ public record Role(Snowflake Id, string Name, int Position, Color? Color) : IHas
     public static Role Parse(JsonElement json)
     {
         var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
-        var name = json.GetProperty("name").GetNonWhiteSpaceString();
+        var name = json.GetProperty("name").GetNonNullString();
         var position = json.GetProperty("position").GetInt32();
 
         var color = json

DiscordChatExporter.Core/Discord/Data/User.cs

@@ -38,7 +38,7 @@ public partial record User
         var id = json.GetProperty("id").GetNonWhiteSpaceString().Pipe(Snowflake.Parse);
         var isBot = json.GetPropertyOrNull("bot")?.GetBooleanOrNull() ?? false;
         var discriminator = json.GetProperty("discriminator").GetNonWhiteSpaceString().Pipe(int.Parse);
-        var name = json.GetProperty("username").GetNonWhiteSpaceString();
+        var name = json.GetProperty("username").GetNonNullString();
         var avatarHash = json.GetPropertyOrNull("avatar")?.GetNonWhiteSpaceStringOrNull();
 
         var avatarUrl = !string.IsNullOrWhiteSpace(avatarHash)