Set up audio controls

[illright]

This should probably be a single component, a feature in terms of Feature Sliced Design.

Acceptance criteria:

• it allows pausing/resuming playback
• it allows jumping forward 30s
• it allows jumping backward 10s
• it allows scrubbing
• it is integrated with the <audio> element that is in the layout (i.e. it doesn't add its own <audio> element)
• it is covered with unit tests

P.S. don't spend too much time styling, just use plain HTML