Add UI setting components (#13550)

Adds some of the UI components to allow us to visually render settings.

These are UI only and are not functional yet (@maxdeviant will be
working on these when he is back.)

You can see some examples by running `script/storybook setting`.

![CleanShot 2024-06-26 at 12 38
37@2x](https://github.com/zed-industries/zed/assets/1714999/b5e6434d-3bc5-4fcd-9c0a-d280950cbef2)

Release Notes:

- N/A

crates/ui/src/selectable.rs

@@ -29,3 +29,23 @@ impl Selection {
         }
     }
 }
+
+impl From<bool> for Selection {
+    fn from(selected: bool) -> Self {
+        if selected {
+            Self::Selected
+        } else {
+            Self::Unselected
+        }
+    }
+}
+
+impl From<Option<bool>> for Selection {
+    fn from(selected: Option<bool>) -> Self {
+        match selected {
+            Some(true) => Self::Selected,
+            Some(false) => Self::Unselected,
+            None => Self::Unselected,
+        }
+    }
+}