Beat Saber Map.rs

Implemented info.dat version: 2.0.0
Implemented beatmap version: 3.2.0 (supports 2.0.0 too)
Latest as of Beat Saber 1.24.0

Beat Saber beatmap types with a parser, implemented with Serde, following the BSMG Wiki.

WIP

This probably works (can't thoroughly check atm), albeit with quite big drawbacks:

• Messy structure (lightning system should've been left as it is...)
• No dumping support at the moment, kinda plan to do it

lib.rs:

See [Beatmap] and [BeatmapSetMeta]