Visualizer doesn't stop when queue is closed

Steps to reproduce

1. Create a queue of content
2. Switch the view mode to visualizer
3. Minimize the queue

What happens?

The visualizer continues to run resulting in a series of errors as the visualizer cycles through presets

What is expected?

The visualizer should stop when the queue closes, and start again when it opens.

Context

Funkwhale version(s) affected: 1.2.8+git.28e5cc6e

output