component: Add component and component_preview crates to power UI components (#24456)

This PR formalizes design components with the Component and
ComponentPreview traits.

You can open the preview UI with `workspace: open component preview`.

Component previews no longer need to return `Self` allowing for more
complex previews, and previews of components like `ui::Tooltip` that
supplement other components rather than are rendered by default.

`cargo-machete` incorrectly identifies `linkme` as an unused dep on
crates that have components deriving `IntoComponent`, so you may need to
add this to that crate's `Cargo.toml`:

```toml
# cargo-machete doesn't understand that linkme is used in the component macro
[package.metadata.cargo-machete]
ignored = ["linkme"]
```

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

crates/workspace/src/workspace.rs

@@ -148,6 +148,7 @@ actions!(
         Open,
         OpenFiles,
         OpenInTerminal,
+        OpenComponentPreview,
         ReloadActiveItem,
         SaveAs,
         SaveWithoutFormat,
@@ -378,6 +379,7 @@ fn prompt_and_open_paths(app_state: Arc<AppState>, options: PathPromptOptions, c
 
 pub fn init(app_state: Arc<AppState>, cx: &mut App) {
     init_settings(cx);
+    component::init();
     theme_preview::init(cx);
 
     cx.on_action(Workspace::close_global);