Add a basic React implementation of the map.

See client/README.md for instructions.

client/src/App.tsx

@@ -0,0 +1,35 @@
+import { LatLng } from "leaflet";
+import "./App.css";
+
+import { LiberationMap } from "./map/liberationmap/LiberationMap";
+import { ControlPoint } from "./game/controlpoint";
+import { useEffect } from "react";
+import { useAppDispatch } from "./app/hooks";
+import { setControlPoints } from "./game/theater/theaterSlice";
+import axios from "axios";
+
+function App() {
+  const mapCenter: LatLng = new LatLng(25.58, 54.9);
+
+  const dispatch = useAppDispatch();
+
+  useEffect(() => {
+    axios
+      .get("http://[::1]:5000/control-points")
+      .catch((error) => console.log(`Error fetching control points: ${error}`))
+      .then((response) => {
+        if (response != null) {
+          dispatch(setControlPoints(response.data as ControlPoint[]));
+        }
+      });
+  });
+
+  console.log(`mapCenter=${mapCenter}`);
+  return (
+    <div className="App">
+      <LiberationMap mapCenter={mapCenter} />
+    </div>
+  );
+}
+
+export default App;