Fix IndentGuides story (#32781)

This PR updates the `Model` to `Entity` also fixes the
`IndentGuidesStory`. In this
[commit](6fca1d2b0b),
`Entity<T>` replaces `View<T>`/`Model<T>`.

Other than this, I noticed the storybook fails on my MacOS and Ubuntu,
see error below

```
thread 'main' panicked at crates/gpui/src/colors.rs:99:15:
called `Result::unwrap()` on an `Err` value: no state of type gpui::colors::GlobalColors exists
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

This was resolved by explicitly specifying `GlobalColors` in Storybook.

Release Notes:

- N/A

crates/ui_input/src/ui_input.rs

@@ -29,7 +29,7 @@ pub struct SingleLineInput {
     label: Option<SharedString>,
     /// The placeholder text for the text field.
     placeholder: SharedString,
-    /// Exposes the underlying [`Model<Editor>`] to allow for customizing the editor beyond the provided API.
+    /// Exposes the underlying [`Entity<Editor>`] to allow for customizing the editor beyond the provided API.
     ///
     /// This likely will only be public in the short term, ideally the API will be expanded to cover necessary use cases.
     pub editor: Entity<Editor>,