feat: support configurable captcha(reCaptcha & hCaptcha) (#765)

* feat: support configurable captcha(layered architecture)

* refactor & add captcha logo

* rename captcha

* Update authz.go

* Update hcaptcha.go

* Update default.go

* Update recaptcha.go

Co-authored-by: Gucheng <85475922+nomeguy@users.noreply.github.com>

web/src/common/CaptchaWidget.js

@@ -0,0 +1,62 @@
+// Copyright 2022 The Casdoor Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import React, { useEffect } from "react";
+
+export const CaptchaWidget = ({ captchaType, siteKey, onChange }) => {
+  const loadScript = (src) => {
+    var tag = document.createElement("script");
+    tag.async = false;
+    tag.src = src;
+    var body = document.getElementsByTagName("body")[0];
+    body.appendChild(tag);
+  };
+
+  useEffect(() => {
+    switch (captchaType) {
+      case "reCAPTCHA":
+        const reTimer = setInterval(() => {
+          if (!window.grecaptcha) {
+            loadScript("https://recaptcha.net/recaptcha/api.js");
+          }
+          if (window.grecaptcha) {
+            window.grecaptcha.render("captcha", {
+              sitekey: siteKey,
+              callback: onChange,
+            });
+            clearInterval(reTimer);
+          }
+        }, 300);
+        break;
+      case "hCaptcha":
+        const hTimer = setInterval(() => {
+          if (!window.hcaptcha) {
+            loadScript("https://js.hcaptcha.com/1/api.js");
+          }
+          if (window.hcaptcha) {
+            window.hcaptcha.render("captcha", {
+              sitekey: siteKey,
+              callback: onChange,
+            });
+            clearInterval(hTimer);
+          }
+        }, 300);
+        break;
+      default:
+        break;
+    }
+  }, [captchaType, siteKey]);
+
+  return <div id="captcha"></div>;
+};