allow export derive macro to name effect

[StuartHarris]

Modifies the Export derive macro so that it respects the name set by the effect attribute for the Effect derive macro. This allows the following to work, creating MyEffectFfi to match the MyEffect type.

#[cfg_attr(feature = "typegen", derive(crux_core::macros::Export))]
#[derive(crux_core::macros::Effect)]
#[effect(name = "MyEffect", app = "NoteEditor")]
pub struct Capabilities {
    timer: Timer<Event>,
    render: Render<Event>,
    pub_sub: PubSub<Event>,
    key_value: KeyValue<Event>,
}

[charypar]

Huh, I would've sworn we already had this. 🤔

[charypar]

Should we add a test using this as well?