feat: re-export bollard

This is extrimely useful if someone wants to utilize `docker_client_instance` and work with docker API in their code utilizing pre-configured client.
However it also assumes user will need corresponding `bollard` types and version allignment.

This PR solves this

Author: DDtKey

testcontainers/src/lib.rs

@@ -95,3 +95,8 @@ mod images;
 pub use images::generic::GenericImage;
 
 pub mod runners;
+
+/// Re-export of the `bollard` crate to allow direct interaction with the Docker API.
+/// This also solves potential version conflicts between `testcontainers` and `bollard` deps.
+pub use bollard;
+pub use bollard_stubs;