AG-1053 Tidy react examples, make more idiomatic

src-examples/dynamicComponentExample/ChildMessageRenderer.jsx

@@ -0,0 +1,20 @@
+import React, {Component} from "react";
+
+export default class ChildMessageRenderer extends Component {
+    constructor(props) {
+        super(props);
+    }
+
+    invokeParentMethod = () => {
+        let rowIndex = this.props.node.rowIndex;
+        let headerName = this.props.colDef.headerName;
+
+        this.props.context.componentParent.methodFromParent(`Row: ${rowIndex}, Col: ${headerName}`)
+    };
+
+    render() {
+        return (
+            <span><button style={{height: 20, lineHeight: 0.5}} onClick={this.invokeParentMethod} className="btn btn-info">Invoke Parent</button></span>
+        );
+    }
+};