Rename Drawable::boxed to into_element and make containers generic

Multi-element are now generic over any drawable child, which can be converted
into an element.

Co-Authored-By: Nathan Sobo <nathan@zed.dev>
Co-Authored-By: Max Brunsfeld <max@zed.dev>

crates/recent_projects/src/highlighted_workspace_location.rs

@@ -45,7 +45,7 @@ impl HighlightedText {
     pub fn render<V: View>(self, style: impl Into<LabelStyle>) -> Element<V> {
         Label::new(self.text, style)
             .with_highlights(self.highlight_positions)
-            .boxed()
+            .into_element()
     }
 }
 

crates/recent_projects/src/recent_projects.rs

@@ -177,6 +177,6 @@ impl PickerDelegate for RecentProjectsDelegate {
             .flex(1., false)
             .contained()
             .with_style(style.container)
-            .named("match")
+            .into_named_element("match")
     }
 }