Upload/Download certs zip from Flipper

Summary:
This diff adds upload and download logic for certs. It makes changes on both Flipper Client and Desktop side. With this we enable cert exchange through WWW.

Next Diffs:

1) Add Flipper state in cert provider for more debug data
2) Tests

Reviewed By: jknoxville

Differential Revision: D23092706

fbshipit-source-id: e576253606b64b62848b70203db7e09a3bd77fd9

desktop/app/src/devices/ClientDevice.tsx

@@ -0,0 +1,17 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import BaseDevice, {OS} from './BaseDevice';
+
+export default class ClientDevice extends BaseDevice {
+  constructor(serial: string, title: string, os: OS) {
+    super(serial, 'emulator', title, os);
+    this.devicePlugins = [];
+  }
+}