Make Encoding URL more compliant to S3 spec (#7360)

There is no written specification about how to encode key names
when url encoding type is passed.

However, this change will encode URLs as url.QueryEscape() does
while considering AWS S3 exceptions.

cmd/api-response.go

@@ -305,21 +305,6 @@ func getObjectLocation(r *http.Request, domains []string, bucket, object string)
 	return u.String()
 }
 
-// s3EncodeName encodes string in response when encodingType
-// is specified in AWS S3 requests.
-func s3EncodeName(name string, encodingType string) (result string) {
-	// Quick path to exit
-	if encodingType == "" {
-		return name
-	}
-	encodingType = strings.ToLower(encodingType)
-	switch encodingType {
-	case "url":
-		return url.QueryEscape(name)
-	}
-	return name
-}
-
 // generates ListBucketsResponse from array of BucketInfo which can be
 // serialized to match XML and JSON API spec output.
 func generateListBucketsResponse(buckets []BucketInfo) ListBucketsResponse {