[datasource editor] Only one click target for edit action (#8495)

superset/assets/src/explore/components/controls/DatasourceControl.css

@@ -0,0 +1,35 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.
+ */
+#datasource_menu {
+    border-radius: 2px;
+    padding-left: 8px;
+    padding-right: 8px;
+}
+
+#datasource_menu .caret {
+    position: relative;
+    padding-right: 8px;
+    margin-left: 4px;
+    color: #fff;
+    top: -8px;
+}
+
+#datasource_menu + ul {
+    margin-top: 26px;
+}