feat: initial integration behaviortreecpp

[cktii]

This is an initial integration for BehaviorTree.CPP (website, repo) a popular library that allows to e.g., structure the switching between different tasks in an autonomous agent, such as a robot or a virtual entity in a computer game.

This PR can be reviewed but needs to wait until the BehaviorTree/BehaviorTree.CPP#925 PR is merged and the harnesses land upstream.

Also, @facontidavide or @miccol either of you as a core-maintainer need to agree on this onboarding of the project here, so if you do, please just ACK this.

[github-actions]

cktii is integrating a new project:
- Main repo: https://github.com/BehaviorTree/BehaviorTree.CPP
- Criticality score: 0.61056

[cktii]

For the sake of completion:

Major Users of the Project:

• ROS2 (Robot Operating System) community uses it extensively for robot behavior control
• Navigation2 (Nav2) project, which is the standard navigation framework for ROS2
• Several robotics companies and research institutions working with ROS2
• Various autonomous systems projects that require sophisticated decision-making

Criticality of the Project:

• Critical for autonomous robot control systems where reliable decision-making is essential for safety
• Used in production environments for industrial robots and autonomous systems
• Core component for behavior control in many ROS2-based applications
• Failures in behavior tree execution could lead to unpredictable robot behavior, making security critical
• Actively maintained and integrated into major robotics frameworks

[jonathanmetzman]

Why isn't this using the real repo?

[jonathanmetzman]

No worries, i'm asking the committee if they approve the integration

[cktii]

Why isn't this using the real repo?

Was a rough day. Fixing it asap tomorrow.

PS: Deleted first reply from personal account 😭