fix: send stickers in message if present

include/dpp/message.h

@@ -1848,7 +1848,7 @@ struct DPP_EXPORT message : public managed, json_interface<message> {
 	snowflake webhook_id;
 
 	/**
-	 * @brief Stickers.
+	 * @brief Partial stickers. Only id, name and format_type are filled
 	 */
 	std::vector<sticker> stickers;
 

src/dpp/message.cpp

@@ -942,6 +942,12 @@ json message::to_json(bool with_id, bool is_interaction_response) const {
 		}
 	}
 
+	if (stickers.size()) {
+		auto [it, _] = j.emplace("sticker_ids", json::array());
+		for (const sticker &s : stickers) {
+			it->push_back(std::to_string(s.id));
+		}
+	}
 
 	j["components"] = json::array();
 	for (auto & component : components) {