colcon-common-extensions: ROS 2 Build Tool Bundle

colcon-common-extensions is a meta-package that aggregates `colcon-core` and several common `colcon` extensions, providing a comprehensive build system for ROS 2 and other robotics projects. It does not provide functionality itself, but ensures a consistent set of `colcon` features are installed. The current version is 0.3.0, and it follows the release cadence of its underlying `colcon-*` dependencies, often aligning with ROS 2 distribution releases.