feat: add icon to graph nodes #918 (#1117)

### What problem does this PR solve?

feat: add icon to graph nodes #918

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/flow/operator-icon/index.less

@@ -0,0 +1,4 @@
+.icon {
+  color: rgb(59, 118, 244);
+  font-size: 24px;
+}

web/src/pages/flow/operator-icon/index.tsx

@@ -0,0 +1,16 @@
+import React from 'react';
+import { Operator, operatorIconMap } from '../constant';
+
+import styles from './index.less';
+
+interface IProps {
+  name: Operator;
+  fontSize?: number;
+}
+
+const OperatorIcon = ({ name, fontSize }: IProps) => {
+  const Icon = operatorIconMap[name] || React.Fragment;
+  return <Icon className={styles.icon} style={{ fontSize }}></Icon>;
+};
+
+export default OperatorIcon;