feat: add multi-file type support for Gemini and Claude

- Add file data DTO for structured file handling
- Implement file decoder service
- Update Claude and Gemini relay channels to handle various file types
- Reorganize worker service to cf_worker for clarity
- Update token counter and image service for new file types

service/cf_worker.go

@@ -0,0 +1,29 @@
+package service
+
+import (
+	"bytes"
+	"fmt"
+	"net/http"
+	"one-api/common"
+	"one-api/setting"
+	"strings"
+)
+
+func DoDownloadRequest(originUrl string) (resp *http.Response, err error) {
+	if setting.EnableWorker() {
+		common.SysLog(fmt.Sprintf("downloading file from worker: %s", originUrl))
+		if !strings.HasPrefix(originUrl, "https") {
+			return nil, fmt.Errorf("only support https url")
+		}
+		workerUrl := setting.WorkerUrl
+		if !strings.HasSuffix(workerUrl, "/") {
+			workerUrl += "/"
+		}
+		// post request to worker
+		data := []byte(`{"url":"` + originUrl + `","key":"` + setting.WorkerValidKey + `"}`)
+		return http.Post(setting.WorkerUrl, "application/json", bytes.NewBuffer(data))
+	} else {
+		common.SysLog(fmt.Sprintf("downloading from origin: %s", originUrl))
+		return http.Get(originUrl)
+	}
+}