chore: use Cow instead of String for tooltips (#2838)

A QoL change to align `Tooltip` with other elements like `Label`
Release Notes:

- N/A

crates/workspace/src/pane.rs

@@ -303,10 +303,10 @@ impl Pane {
                         let tooltip_label;
                         if pane.is_zoomed() {
                             icon_path = "icons/minimize_8.svg";
-                            tooltip_label = "Zoom In".into();
+                            tooltip_label = "Zoom In";
                         } else {
                             icon_path = "icons/maximize_8.svg";
-                            tooltip_label = "Zoom In".into();
+                            tooltip_label = "Zoom In";
                         }
 
                         Pane::render_tab_bar_button(
@@ -1477,7 +1477,7 @@ impl Pane {
         index: usize,
         icon: &'static str,
         is_active: bool,
-        tooltip: Option<(String, Option<Box<dyn Action>>)>,
+        tooltip: Option<(&'static str, Option<Box<dyn Action>>)>,
         cx: &mut ViewContext<Pane>,
         on_click: F1,
         on_down: F2,

crates/workspace/src/toolbar.rs

@@ -220,7 +220,7 @@ fn nav_button<A: Action, F: 'static + Fn(&mut Toolbar, &mut ViewContext<Toolbar>
     spacing: f32,
     on_click: F,
     tooltip_action: A,
-    action_name: &str,
+    action_name: &'static str,
     cx: &mut ViewContext<Toolbar>,
 ) -> AnyElement<Toolbar> {
     MouseEventHandler::<A, _>::new(0, cx, |state, _| {
@@ -252,7 +252,7 @@ fn nav_button<A: Action, F: 'static + Fn(&mut Toolbar, &mut ViewContext<Toolbar>
     })
     .with_tooltip::<A>(
         0,
-        action_name.to_string(),
+        action_name,
         Some(Box::new(tooltip_action)),
         tooltip_style,
         cx,