Move the document trait into a separate crate (#3035)

* add a default head method through eval
* remove the old document trait
* implement document for each platform
* pull out document into a dedicated crate to cut down on shared dependencies
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Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

packages/core/src/scheduler.rs

@@ -32,7 +32,7 @@
 //!     use_effect(move || {
 //!         let id = id.read();
 //!         // This will panic if the id is not written to the DOM before the effect is run
-//!         eval(format!(r#"document.getElementById("{id}").innerHTML = "Hello World";"#));
+//!         document::eval(format!(r#"document.getElementById("{id}").innerHTML = "Hello World";"#));
 //!     });
 //!
 //!     rsx! {