Add user locale & guild locale in interactions (#2040)

src/Discord.Net.Rest/API/Common/Interaction.cs

@@ -37,5 +37,11 @@ namespace Discord.API
 
         [JsonProperty("message")]
         public Optional<Message> Message { get; set; }
+
+        [JsonProperty("locale")]
+        public Optional<string> UserLocale { get; set; }
+
+        [JsonProperty("guild_locale")]
+        public Optional<string> GuildLocale { get; set; }
     }
 }

src/Discord.Net.Rest/Entities/Interactions/RestInteraction.cs

@@ -32,6 +32,12 @@ namespace Discord.Rest
         /// </summary>
         public RestUser User { get; private set; }
 
+        /// <inheritdoc/>
+        public string UserLocale { get; private set; }
+
+        /// <inheritdoc/>
+        public string GuildLocale { get; private set; }
+
         /// <inheritdoc/>
         public DateTimeOffset CreatedAt { get; private set; }
 
@@ -126,6 +132,13 @@ namespace Discord.Rest
             {
                 Channel = (IRestMessageChannel)await discord.GetChannelAsync(model.ChannelId.Value);
             }
+
+            UserLocale = model.UserLocale.IsSpecified
+               ? model.UserLocale.Value
+               : null;
+            GuildLocale = model.GuildLocale.IsSpecified
+                ? model.GuildLocale.Value
+                : null;
         }
 
         internal string SerializePayload(object payload)