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/src/components/stories/icon.rs

@@ -1,20 +0,0 @@
-use gpui::Render;
-use story::Story;
-use strum::IntoEnumIterator;
-
-use crate::prelude::*;
-use crate::{Icon, IconName};
-
-pub struct IconStory;
-
-impl Render for IconStory {
-    fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
-        let icons = IconName::iter();
-
-        Story::container()
-            .child(Story::title_for::<Icon>())
-            .child(Story::label("DecoratedIcon"))
-            .child(Story::label("All Icons"))
-            .child(div().flex().gap_3().children(icons.map(Icon::new)))
-    }
-}