Add new Button and IconButton components (#3448)

This PR adds new `Button` and `IconButton` components built on top of
our new button abstractions.

Both of these buttons are built from the common `ButtonLike` base, and
implement the `ButtonCommon` (name TBD) trait in order to provide a
common interface.

There are still some visual tweaks that we'll need to make to the new
buttons, but those should be straightforward to make after we land this.

Release Notes:

- N/A

crates/workspace2/src/status_bar.rs

@@ -71,14 +71,14 @@ impl Render for StatusBar {
                                 div()
                                     .border()
                                     .border_color(gpui::red())
-                                    .child(Button::new("15:22")),
+                                    .child(Button::new("status_line_column_numbers", "15:22")),
                             )
                             .child(
                                 // TODO: Language picker
                                 div()
                                     .border()
                                     .border_color(gpui::red())
-                                    .child(Button::new("Rust")),
+                                    .child(Button::new("status_buffer_language", "Rust")),
                             ),
                     )
                     .child(