feat: add FlowHeader and delete edge (#959)

### What problem does this PR solve?
feat: add FlowHeader and delete edge #918 

### Type of change

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

web/src/pages/flow/header/index.tsx

@@ -0,0 +1,26 @@
+import { Button, Flex } from 'antd';
+
+import { useSaveGraph } from '../hooks';
+import styles from './index.less';
+
+const FlowHeader = () => {
+  const { saveGraph } = useSaveGraph();
+
+  return (
+    <Flex
+      align="center"
+      justify="end"
+      gap={'large'}
+      className={styles.flowHeader}
+    >
+      <Button>
+        <b>Debug</b>
+      </Button>
+      <Button type="primary" onClick={saveGraph}>
+        <b>Save</b>
+      </Button>
+    </Flex>
+  );
+};
+
+export default FlowHeader;