Use InputGroup in json-extension

packages/json-extension/package.json

@@ -31,6 +31,7 @@
   },
   "dependencies": {
     "@jupyterlab/rendermime-interfaces": "^1.2.1",
+    "@jupyterlab/ui-components": "^0.0.1",
     "@phosphor/coreutils": "^1.3.0",
     "@phosphor/messaging": "^1.2.2",
     "@phosphor/widgets": "^1.6.0",

packages/json-extension/tsconfig.json

@@ -8,6 +8,9 @@
   "references": [
     {
       "path": "../rendermime-interfaces"
+    },
+    {
+      "path": "../ui-components"
     }
   ]
 }