BeatLeader bug fix

• Fixes issue with new BeatLeader replay UI
• Fixes Colours being defaulted to alpha 0 on first reload of the game when updating to this version of SongCore

SongCore 1.29.1 Backport

Versions below 1.29 are untested but may work

This is a 1.31.0 backport!
This version brings support for the v2.1.0 beatmap format and the Legacy Characteristic.
This does not load any DLC from newer versions as the asset bundles are incompatible with this version of Unity.

Changes:

• Loading of v2.1.0 BeatMaps
• Legacy Characteristic
• You can now see the environment a level uses if it is already showing custom data.
• v2.1.0 Environment override support
• v2.1.0 Custom Colours are now applied as if they are SongCore colours to keep consistency and showcase them within the [ ? ] UI
• Backported the incorrect song length fix

I have also ported over features from PinkCore:

• Editing of Characteristic Labels and Icons
• Forced OneSaber/Standard, if you are remapping a OneSaber map into the Legacy Characteristic, you can now set the level to be a OneSaber level.
• Hiding of the note spawn lines
• The green mapper text has now been changed to the Pink found in PinkCore (My villain arc can be set back to green in the settings)

Information on how to apply the above characteristic editing can be found here:
https://github.com/ModdingPink/SongCoreLegacy#characteristics-editing

If you are having any issues with this specific version of SongCore then please DM me (moddingpink), not Kyle or Eris.