Merge Component and ComponentPreview trait (#28365)

- Merge `Component` and `ComponentPreview` trait
- Adds a number of component previews
- Removes a number of stories

Release Notes:

- N/A

crates/ui_macros/src/derive_register_component.rs

@@ -0,0 +1,25 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{DeriveInput, parse_macro_input};
+
+pub fn derive_register_component(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+    let name = input.ident;
+    let reg_fn_name = syn::Ident::new(
+        &format!("__component_registry_internal_register_{}", name),
+        name.span(),
+    );
+    let expanded = quote! {
+        const _: () = {
+            struct AssertComponent<T: component::Component>(::std::marker::PhantomData<T>);
+            let _ = AssertComponent::<#name>(::std::marker::PhantomData);
+        };
+
+        #[allow(non_snake_case)]
+        #[linkme::distributed_slice(component::__ALL_COMPONENTS)]
+        fn #reg_fn_name() {
+            component::register_component::<#name>();
+        }
+    };
+    expanded.into()
+}