feat: re-export OperationRegistryBuilder from crate root

Downstream crates can now use
instead of the full path .

Verification:
- 542 tests, 0 failed
- cargo clippy --all-targets -- -D warnings: clean
- cargo fmt --check: clean

src/lib.rs

@@ -73,3 +73,5 @@ pub mod client;
 pub mod core;
 pub mod protocol;
 pub mod registry;
+
+pub use registry::registration::OperationRegistryBuilder;