feat: use Show from nowplaypadgen project

[hairmare]

This draft is a first step and i'll likely end up completely replacing the local Show class with the one from nowplaypadgen.

The main things that still need to be taken care of for that to happen are

• replace uuid with uid here or uid with uuid in nowplaypadgen, consider removing uuid fix: uuid instead of uid nowplaypadgen#16
• move DEFAULT_SHOW_URL to config and allow passing one to super in Show
• I'll focus on landing the DLPlus feature from feat: send to DLS+ endpoints if artist/title available #130 first though

Fixes #8 partially