replace implementation module with declarative macro (#313)

The current approach of having a free standing module that is
instantiated multiple times with the explicit `path` often causes
confusion when reading the code. So replace this with a very simple
declarative macro that hopefully is more explicit and simpler than the
current approach.

Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>

src/lib.rs

@@ -54,6 +54,7 @@ mod surface;
 pub use crate::surface::{SurfaceAccess, SurfaceID, SurfaceInfo, SurfaceType, SystemSurfaceInfo};
 
 pub mod macros;
+pub(crate) use macros::implement_interfaces;
 
 #[cfg(not(any(target_os = "android", target_env = "ohos")))]
 pub(crate) use crate::gl::Gl;