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.

relay/channel/api_request.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"net/http"
 	common2 "one-api/common"
+	"one-api/logger"
 	"one-api/relay/common"
 	"one-api/relay/constant"
 	"one-api/relay/helper"
@@ -181,7 +182,7 @@ func sendPingData(c *gin.Context, mutex *sync.Mutex) error {
 
 		err := helper.PingData(c)
 		if err != nil {
-			common2.LogError(c, "SSE ping error: "+err.Error())
+			logger.LogError(c, "SSE ping error: "+err.Error())
 			done <- err
 			return
 		}