Dashboard plugin that throws error crashes UI

[mofojed]

Description

If you run a dashboard plugin that throws in the render cycle, it will crash DH. Instead, it should just log an error and not crash the application.

Steps to reproduce

1. Modify a DashboardPlugin to throw in render
2. Start up the UI

Expected results
2. UI should start, with an error logged about the dashboard plugin that threw

Actual results
2. Deephaven UI crashes.