调整oppo支付，不引用外部包

package/pay/common/func.go

@@ -0,0 +1,30 @@
+package common
+
+import "strings"
+
+func FormatPublicKey(publicKey string) (pKey string) {
+	var buffer strings.Builder
+	buffer.WriteString("-----BEGIN PUBLIC KEY-----\n")
+	rawLen := 64
+	keyLen := len(publicKey)
+	raws := keyLen / rawLen
+	temp := keyLen % rawLen
+	if temp > 0 {
+		raws++
+	}
+	start := 0
+	end := start + rawLen
+	for i := 0; i < raws; i++ {
+		if i == raws-1 {
+			buffer.WriteString(publicKey[start:])
+		} else {
+			buffer.WriteString(publicKey[start:end])
+		}
+		buffer.WriteByte('\n')
+		start += rawLen
+		end = start + rawLen
+	}
+	buffer.WriteString("-----END PUBLIC KEY-----\n")
+	pKey = buffer.String()
+	return
+}