Fix all build warnings

- vk_utils.hpp: mark unused 'msg' parameter with [[maybe_unused]]
- world_packets.cpp: write exactMatch field to auction list packet
  (was accepted as parameter but never serialized)
- game_screen.cpp: remove unused bagIcons array and unused info variable
- talent_screen.cpp: remove unused nextRank and pMin variables

include/rendering/vk_utils.hpp

@@ -48,7 +48,7 @@ AllocatedBuffer uploadBuffer(VkContext& ctx, const void* data, VkDeviceSize size
     VkBufferUsageFlags usage);
 
 // Check VkResult and log on failure
-inline bool vkCheck(VkResult result, const char* msg) {
+inline bool vkCheck(VkResult result, [[maybe_unused]] const char* msg) {
     if (result != VK_SUCCESS) {
         // Caller should log the message
         return false;