Feat: massive changes to definition of components

This change switches back to the original `ctx<props>` syntax for
commponents. This lets lifetime elision to remove the need to match
exactly which lifetime (props or ctx) gets  carried to the output. As
such, `Props` is currently required to be static. It *is* possible to
loosen this restriction, and will be done in the future, though only
through adding metadata about the props through the Props derive
macro. Implementing the IS_STATIC trait is unsafe, so the derive macro
will do it through some heuristics.

For now, this unlocks sharing vnodes from parents to children, enabling
pass-thru components, fragments, portals, etc.

packages/core-macro/src/fc.rs

@@ -5,9 +5,7 @@ use syn::{
     parse::{Parse, ParseStream},
     Signature,
 };
-use syn::{
-    Attribute, Block, FnArg, Ident, Item, ItemFn, ReturnType, Type, Visibility,
-};
+use syn::{Attribute, Block, FnArg, Ident, Item, ItemFn, ReturnType, Type, Visibility};
 
 /// A parsed version of the user's input
 pub struct FunctionComponent {
@@ -135,7 +133,7 @@ impl ToTokens for FunctionComponent {
             }
 
             impl<'a> FC for #function_name<'a> {
-                fn render(ctx: Context<'_>, props: &#function_name<'a>) -> DomTree {
+                fn render(ctx: Context<'_>, props: &#function_name<'a>) -> VNode {
                     let #function_name {
                         ..
                     } = props;
@@ -244,7 +242,7 @@ pub fn ensure_return_type(output: ReturnType) -> syn::Result<Box<Type>> {
     match output {
         ReturnType::Default => Err(syn::Error::new_spanned(
             output,
-            "function components must return a `DomTree`",
+            "function components must return a `VNode`",
         )),
         ReturnType::Type(_, ty) => Ok(ty),
     }