feat: crash reporting

[eseidel]

Would like more robust automated crash reporting built into Shorebird.

The specific request this morning from a customer was to include the android version in a failure log. (Which would be easy to do, but we don't currently expose the failure events in our console anywhere.) But such a request is part of a more general question of "give me insights into any failures in the field".

We don't have to build such ourselves (we could integrate with sentry or similar). But we also have an opportunity to make crash reporting super easy to add to Flutter apps (without having to add additional dependencies).