add connection modal

web/src/widgets/DatabaseWidget.js

@@ -1,5 +1,13 @@
 import React from 'react';
+import useModalState from '../modals/useModalState';
+import ConnectionModal from '../modals/ConnectionModal';
 
 export default function DatabaseWidget() {
-  return <button onClick={() => {}}>Add connection</button>;
+  const modalState = useModalState();
+  return (
+    <>
+      <ConnectionModal modalState={modalState} />
+      <button onClick={modalState.open}>Add connection</button>
+    </>
+  );
 }