API Improvements / Code Maintenance

[azriel91]

• Change WebStorage to take in &Paths instead of &strs.
• resources_type_state module should be resources::ts.

Provide types that will be inserted into Resources, instead of having a W<'op, Option<T>> and R<'op, Option<T>>
This requires &mut Resources, and while the graph is processing, we only have access to &Resources.

Rough idea:

use resman::Resource;

/// Something included inside a `Data` implementation.
#[derive(Debug)]
pub struct Insert<T> {
    tx: Sender<Box<dyn Resource>>,
}

impl<'borrow, T> Data<'borrow> for Insert<'borrow, T>
where
    T: Debug + Send + Sync + 'static,
{
    fn borrow(_resources: &'borrow Resources) -> Self {
        // no-op, as the ItemSpec will instantiate T.
    }
}

// T must be set before `Insert` is dropped?

impl<'borrow, T> Drop for Insert<'borrow, T>
where
    T: Debug + Send + Sync + 'static,
{
    fn drop() -> Self {
        self.tx.send(t);
    }
}

// Somewhere else in the framework.
// This still can't be inserted during a graph iteration.
let r = rx.receive().await;
resources.insert(t);