Preload storyboard

[Creeperuuu]

Description

Also start loading the storyboard when a beatmap is starting

Justification

It causes lag spike when its trying to load while playing beatmaps on my low end device even i know it may take longer than usual to load a beat map so make it toggleable option

Alternative methods

[Reco1I]

It already does, what causes lag spikes is the rendering itself.

[Rian8337]

Tentatively closing since the issue isn't in the preload but rather the render (which is known).