Feature/ament

[jlack1987]

Changelog

Add option to build as part of a ros2 workspace

Description

Add optional ament check so ros2 users can compile this within a ros2 workspace and depend on it that way.

[achim-k]

For ROS2 users, I would recommend to create a separate ws_protocol_vendor package (in another repo) which exposes the C++ & Python libs to ROS2 packages that depend on it. This would look very similar to mcap_vendor which uses fetchContent under the hood. We could then also use the ws_protocol_vendor package for foxglove/ros-foxglove-bridge#89