Improve StringMatchCandidate::new interface (#22011)

Release Notes:

- N/A

crates/command_palette/src/command_palette.rs

@@ -283,11 +283,7 @@ impl PickerDelegate for CommandPaletteDelegate {
                 let candidates = commands
                     .iter()
                     .enumerate()
-                    .map(|(ix, command)| StringMatchCandidate {
-                        id: ix,
-                        string: command.name.to_string(),
-                        char_bag: command.name.chars().collect(),
-                    })
+                    .map(|(ix, command)| StringMatchCandidate::new(ix, &command.name))
                     .collect::<Vec<_>>();
                 let matches = if query.is_empty() {
                     candidates