Avoiding specialization for resources

[MarcGuiselin]

Bevy currently differentiates resources and components, but steps are being taken to combine the two concepts together. See https://hackmd.io/_uB08OiAT4GqOXPE-X76eQ and bevyengine/bevy#19731

TLDR the long term plan is to unify the two apis such that:

type Res<T: Resource> = Single<&T, With<ResourceEntity<T>>;
type ResMut<T: Resource> = Single<&mut T, With<ResourceEntity<T>>;

In the latest version, resources are already components. But there are still some large api differences between the two.

I think that instead of inheriting the cruft from the current bevy version we build a better, more future-proof api that learns from their design work.

We also need to consider Bevy's specialized use-cases for resources such as the asset system. Should we create a dedicated system param for assets (such as an assets resource in wit) or can we leverage the authoring system in Wasvy? It might be possible to generate bindings for assets directly in such a way that a user can access any Assets<T> resource, without wasvy needing a custom implementation for every asset we want to support.

Todo:

• Determine if we need a special resource resource in wit. Is there any usecase that requires specialization?