Use a Cow<'static, str> for the Info component title

Some uses of the component (like for register) provide a static title.
We can trivially avoid the title allocation in those cases.

helix-term/src/keymap.rs

@@ -106,7 +106,7 @@ impl KeyTrieNode {
                 (events.join(", "), desc)
             })
             .collect();
-        Info::new(&self.name, &body)
+        Info::new(self.name.clone(), &body)
     }
 }
 

helix-term/src/ui/info.rs

@@ -24,7 +24,7 @@ impl Component for Info {
         surface.clear_with(area, popup_style);
 
         let block = Block::bordered()
-            .title(self.title.as_str())
+            .title(self.title.as_ref())
             .border_style(popup_style);
 
         let margin = Margin::horizontal(1);