Refactor lfs requests (#26783)

- Refactor lfs request code
- The original code uses `performRequest` function to create the
request, uses a callback to modify the request, and then send the
request.
- Now it's replaced with `createRequest` that only creates request and
`performRequest` that only sends the request.
- Reuse `createRequest` and `performRequest` in `http_client.go` and
`transferadapter.go`

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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/util/path.go

@@ -225,6 +225,7 @@ func isOSWindows() bool {
 var driveLetterRegexp = regexp.MustCompile("/[A-Za-z]:/")
 
 // FileURLToPath extracts the path information from a file://... url.
+// It returns an error only if the URL is not a file URL.
 func FileURLToPath(u *url.URL) (string, error) {
 	if u.Scheme != "file" {
 		return "", errors.New("URL scheme is not 'file': " + u.String())