Added tracepoint for rclcpp_take event when message loaning is used

[nightduck]

Description

It's difficult to fully trace a system when using zero-copy because the rclcpp_take tracepoint is not invoked. This corrects for that.

Is this user-facing behavior change?

No

Did you use Generative AI?

No

Additional Information

[jmachowinski]

I would rather add the tracepoint to rcl_take_loaned_message, as the tracepoint for rcl_take is also in rcl.
This would also fix rclpy tracing as well.

[nightduck]

When a message take is performed, there's 3 trace points called: rclcpp_take, rcl_take, and rmw_take. I'm already working on the last 2 with PRs in other packages. But rclcpp_take doesn't get triggered when subscription->can_loan_messages() is true