Enable beluga_amcl ROS 2 nodes' autostart

[hidmic]

Proposed changes

This patch adds an autostart feature for beluga_amcl nodes to configure and activate themselves on demand, providing for systems that lack (or avoid) lifecycle management. It is also a escape hatch for Beluga to be usable in ROS 2 without explicitly providing a nav2_lifecycle_manager substitute.

Type of change

• 🐛 Bugfix (change which fixes an issue)
• 🚀 Feature (change which adds functionality)
• 📚 Documentation (change which fixes or extends documentation)

Checklist

• Lint and unit tests (if any) pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• All commits have been signed for DCO

[nahueespinosa]

LGTM