Add client_id support for OpenID (#8579)

- One click OpenID authorization on Login page
- Add client_id help, config keys etc

Thanks to @egorkaru @ihostage for the
original work and testing.

browser/app/js/browser/utils.js

@@ -0,0 +1,29 @@
+/*
+ * MinIO Cloud Storage (C) 2019 MinIO, Inc.
+ *
+ * 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.
+ */
+
+export const OPEN_ID_NONCE_KEY = 'openIDKey'
+
+export const buildOpenIDAuthURL = (authorizationEndpoint, redirectURI, clientID, nonce) => {
+  const params = new URLSearchParams()
+  params.set("response_type", "id_token")
+  params.set("scope", "openid")
+  params.set("client_id", clientID)
+  params.set("redirect_uri", redirectURI)
+  params.set("nonce", nonce)
+
+  return `${authorizationEndpoint}?${params.toString()}`
+}
+