Factor out LabelLike to share common label styles (#3510)

This PR factors out a new `LabelLike` component to share common styles
between the `Label` and `HighlightedLabel` components.

Release Notes:

- N/A

crates/diagnostics2/src/diagnostics.rs

@@ -36,7 +36,7 @@ use std::{
 };
 use theme::ActiveTheme;
 pub use toolbar_controls::ToolbarControls;
-use ui::{h_stack, Color, HighlightedLabel, Icon, IconElement, Label};
+use ui::{h_stack, prelude::*, HighlightedLabel, Icon, IconElement, Label};
 use util::TryFutureExt;
 use workspace::{
     item::{BreadcrumbText, Item, ItemEvent, ItemHandle},