Restructure ui into just elements and components (#3023)

This PR restructures the `ui` crate into just `elements` and
`components`.

This was already done on the `gpui2-ui` branch, just getting it onto
`main`.

Release Notes:

- N/A

---------

Co-authored-by: Nate Butler <nate@zed.dev>

crates/ui/src/lib.rs

@@ -3,10 +3,8 @@
 mod components;
 mod element_ext;
 mod elements;
-mod modules;
 pub mod prelude;
 mod static_data;
-mod templates;
 mod theme;
 mod tokens;
 
@@ -14,8 +12,6 @@ pub use crate::theme::*;
 pub use components::*;
 pub use element_ext::*;
 pub use elements::*;
-pub use modules::*;
 pub use prelude::*;
 pub use static_data::*;
-pub use templates::*;
 pub use tokens::*;