Subtree memorization / reactive templates (#488)

This commit adds subtree memoization to Dioxus.

Subtree memoization is basically a compile-time step that drastically 
reduces the amount of work the diffing engine needs to do at runtime by
extracting non-changing nodes out into a static "template." Templates 
are then understood by the various renderers in the ecosystem as a 
faster way of rendering the same items. 

For example, in the web, templates are simply a set of DOM Nodes created 
once and then cloned later. This is the same pattern frameworks like Lithtml
and SolidJS use to achieve near-perfect performance. 

Subtree memoization adds an additional level of complexity to Dioxus. The RSX
macro needs to be much smarter to identify changing/nonchanging nodes and
generate a mapping between the Template and its runtime counterparts.

This commit represents a working starter point for this work, adding support 
for templates for the web, desktop, liveview, ssr, and native-core renderers.
In the future we will try to shrink code generation, generally improve 
performance, and simplify our implementation.

packages/html/src/global_attributes.rs

@@ -1,5 +1,4 @@
 use dioxus_core::*;
-use std::fmt::Arguments;
 
 macro_rules! no_namespace_trait_methods {
     (
@@ -9,10 +8,12 @@ macro_rules! no_namespace_trait_methods {
         )*
     ) => {
         $(
-            $(#[$attr])*
-            fn $name<'a>(&self, cx: NodeFactory<'a>, val: Arguments) -> Attribute<'a> {
-                cx.attr(stringify!($name), val, None, false)
-            }
+            #[allow(non_upper_case_globals)]
+            const $name: AttributeDiscription = AttributeDiscription{
+                name: stringify!($name),
+                namespace: None,
+                volatile: false
+            };
         )*
     };
 }
@@ -24,11 +25,12 @@ macro_rules! style_trait_methods {
         )*
     ) => {
         $(
-            #[inline]
-            $(#[$attr])*
-            fn $name<'a>(&self, cx: NodeFactory<'a>, val: Arguments) -> Attribute<'a> {
-                cx.attr($lit, val, Some("style"), false)
-            }
+            #[allow(non_upper_case_globals)]
+            const $name: AttributeDiscription = AttributeDiscription{
+                name: $lit,
+                namespace: Some("style"),
+                volatile: false
+            };
         )*
     };
 }
@@ -40,10 +42,12 @@ macro_rules! aria_trait_methods {
         )*
     ) => {
         $(
-            $(#[$attr])*
-            fn $name<'a>(&self, cx: NodeFactory<'a>, val: Arguments) -> Attribute<'a> {
-                cx.attr($lit, val, None, false)
-            }
+            #[allow(non_upper_case_globals)]
+            const $name: AttributeDiscription = AttributeDiscription{
+                name: $lit,
+                namespace: None,
+                volatile: false
+            };
         )*
     };
 }
@@ -53,9 +57,12 @@ pub trait GlobalAttributes {
     ///
     /// For more information, see the MDN docs:
     /// <https://developer.mozilla.org/en-US/docs/Web/API/Event/preventDefault>
-    fn prevent_default<'a>(&self, cx: NodeFactory<'a>, val: Arguments) -> Attribute<'a> {
-        cx.attr("dioxus-prevent-default", val, None, false)
-    }
+    #[allow(non_upper_case_globals)]
+    const prevent_default: AttributeDiscription = AttributeDiscription {
+        name: "dioxus-prevent-default",
+        namespace: None,
+        volatile: false,
+    };
 
     no_namespace_trait_methods! {
         accesskey;
@@ -597,9 +604,12 @@ pub trait SvgAttributes {
     ///
     /// For more information, see the MDN docs:
     /// <https://developer.mozilla.org/en-US/docs/Web/API/Event/preventDefault>
-    fn prevent_default<'a>(&self, cx: NodeFactory<'a>, val: Arguments) -> Attribute<'a> {
-        cx.attr("dioxus-prevent-default", val, None, false)
-    }
+    #[allow(non_upper_case_globals)]
+    const prevent_default: AttributeDiscription = AttributeDiscription {
+        name: "dioxus-prevent-default",
+        namespace: None,
+        volatile: false,
+    };
     aria_trait_methods! {
         accent_height: "accent-height",
         accumulate: "accumulate",