UI for sharable URLs

Summary:
Uploading the Flipper data could take some while. With the current implementation the user didn't know what was happening. This is why this diff immediately shows a sheet with a spinner, until the upload is finished.

The URL is still copied to the clipboard and a notifications is displayed. Additionally the user can copy the URL from the sheet.

Reviewed By: priteshrnandgaonkar

Differential Revision: D14441759

fbshipit-source-id: c853526a7da76e2dea5e1aaf6b6eff21e4268789

src/fb-stubs/user.js

@@ -17,7 +17,23 @@ export function logoutUser(): Promise<void> {
   return Promise.reject();
 }
 
-export async function shareFlipperData(trace: string) {
+export async function shareFlipperData(
+  trace: string,
+): Promise<
+  | {
+      id: string,
+      os: 'string',
+      deviceType: string,
+      plugins: string[],
+      fileUrl: string,
+      flipperUrl: string,
+    }
+  | {
+      error: string,
+      error_class: string,
+      stacktrace: string,
+    },
+> {
   new window.Notification('Feature not implemented');
   return Promise.reject();
 }