Revert "Revert recent anti-aliasing improvements (#24289)" and fix selection top right corner radius issue (#24342)

Release Notes:

- N/A

----

To fix #24289 mention issue and revert PathBuilder and MSAA.

I'm sorry about of this, in #22808 I was forgotten this bit of detail.


![image](https://github.com/user-attachments/assets/112afda2-088c-41d0-83bd-808f6cd2f9d5)

So, add `move_to` here, we can fix the selection top right corner radius
issue.

## After change

<img width="1383" alt="image"
src="https://github.com/user-attachments/assets/28ea103c-d652-41d6-bbe0-7fd042d81e77"
/>

crates/gpui/src/gpui.rs

@@ -82,6 +82,7 @@ mod input;
 mod interactive;
 mod key_dispatch;
 mod keymap;
+mod path_builder;
 mod platform;
 pub mod prelude;
 mod scene;
@@ -135,6 +136,7 @@ pub use input::*;
 pub use interactive::*;
 use key_dispatch::*;
 pub use keymap::*;
+pub use path_builder::*;
 pub use platform::*;
 pub use refineable::*;
 pub use scene::*;