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
---------

Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

packages/document/src/lib.rs

@@ -0,0 +1,31 @@
+use std::rc::Rc;
+
+mod document;
+mod elements;
+mod error;
+mod eval;
+
+pub use document::*;
+pub use elements::*;
+pub use error::*;
+pub use eval::*;
+
+/// Get the document provider for the current platform or a no-op provider if the platform doesn't document functionality.
+pub fn document() -> Rc<dyn Document> {
+    match dioxus_core::prelude::try_consume_context::<Rc<dyn Document>>() {
+        Some(document) => document,
+        None => {
+            tracing::error!(
+                "Unable to find a document in the renderer. Using the default no-op document."
+            );
+            Rc::new(NoOpDocument)
+        }
+    }
+}
+
+/// Evaluate some javascript in the current document
+#[doc = include_str!("../docs/eval.md")]
+#[doc(alias = "javascript")]
+pub fn eval(script: &str) -> Eval {
+    document().eval(script.to_string())
+}