refactor: Introduce pre-consume quota and unify relay handlers

This commit introduces a major architectural refactoring to improve quota management, centralize logging, and streamline the relay handling logic.

Key changes:
- **Pre-consume Quota:** Implements a new mechanism to check and reserve user quota *before* making the request to the upstream provider. This ensures more accurate quota deduction and prevents users from exceeding their limits due to concurrent requests.

- **Unified Relay Handlers:** Refactors the relay logic to use generic handlers (e.g., `ChatHandler`, `ImageHandler`) instead of provider-specific implementations. This significantly reduces code duplication and simplifies adding new channels.

- **Centralized Logger:** A new dedicated `logger` package is introduced, and all system logging calls are migrated to use it, moving this responsibility out of the `common` package.

- **Code Reorganization:** DTOs are generalized (e.g., `dalle.go` -> `openai_image.go`) and utility code is moved to more appropriate packages (e.g., `common/http.go` -> `service/http.go`) for better code structure.

setting/chat.go

@@ -2,7 +2,7 @@ package setting
 
 import (
 	"encoding/json"
-	"one-api/common"
+	"one-api/logger"
 )
 
 var Chats = []map[string]string{
@@ -37,7 +37,7 @@ func UpdateChatsByJsonString(jsonString string) error {
 func Chats2JsonString() string {
 	jsonBytes, err := json.Marshal(Chats)
 	if err != nil {
-		common.SysError("error marshalling chats: " + err.Error())
+		logger.SysError("error marshalling chats: " + err.Error())
 		return "[]"
 	}
 	return string(jsonBytes)