Update RO2 publisher sink to use NodeInterfaces

[coderjake91]

Hello!

First off — thanks for creating DataTamer. It’s an awesome library.

I’ve been developing a ROS2 Jazzy system using a composition-based architecture with both lifecycle and regular nodes. We use DataTamer to collect time-series data and pipe it into Foxglove, and the ROS2 publisher sink makes that integration super smooth.

I ran into an issue when adding the ROS2 publisher sink inside composable nodes. In composition, node ownership changes — the executor owns the shared pointer and spins the nodes — so you often don’t have direct access to the node shared_ptr in the same way as when running standalone nodes. This affects both lifecycle and regular nodes.

I tried workarounds like shared_from_this(), but those are fragile and can easily lead to invalid weak pointers.

I noticed recent support for lifecycle nodes was added via additional constructor overloads, and this PR builds on that idea by updating ROS2PublisherSink to accept a NodeInterfaces façade instead of requiring a shared_ptr. Since this sink only needs the topics interface, this lets users pass either:

1. A NodeInterfaces object directly
2. A Node / LifecycleNode
3. A shared_ptr to either

while remaining fully backwards compatible.

I took my colleague @jlack1987’s advice (he’s been working with DataTamer for a while) and structured this to preserve all existing usage patterns.

Thanks again — happy to adjust anything if needed!

[coderjake91]

Also, I added new ROS2 Publisher Sink Tests in: data_tamer_cpp/tests/ros2_publisher_tests.cpp