Feature: native visualizer

[tranzystorekk]

Moving discussion about a future reimplementation of visualiser from #7 here.

Established so far:

• I created a demo visualizer with ratatui and a custom libcava/cavacore rust FFI wrapper library, the latter I'm planning on publishing once I've got some wrinkles ironed out. So far it only works if there's a libcava installation with a pkg-config setup available on system. So far changes necessary for that have been living in a fork: https://github.com/LukashonakV/cava and upstream is reluctant to merge them in.
• Symphonia seems to provide the captured and decoded samples that libcava-rs requires, with dasp_sample it should also be trivial to reconvert them to the f64 format that cava accepts. Hopefully this makes tori as crossplatform as it gets!

Here's the newest version of the demo 😊

https://github.com/LeoRiether/tori/assets/5671049/11f7496a-5da4-49ac-83dc-e10e90740625