Establish discovery system and add support for /areas network endpoint.

[mfaferek93]

Feature request / General issue

Discovery Manager to:

• Discover ROS 2 nodes and namespaces using node graph API
• Extract area hierarchy from namespaces

REST server extension to support GET /areas - List discovered areas

Demo nodes to test and show /areas endpoint implementation, e.g.

• /powertrain/engine: temp_sensor, rpm_sensor, calibration service
• /chassis/brakes: pressure_sensor, actuator
• /body/door/front_left: status_sensor
• /body/lights: controller

Postman config file for easier testing.

Gateway node extensions with configuration options for periodic discovery cache time and server endpoints (address and port)

Proposal

See above

Motivation

Supporting nodes discovery with proper areas matching based on namespaces.

Alternatives considered

I propose to implement nodes discovery based on ros2 cli to avoid additional complexities in early project stages and quickly deliver something working (incremental MVP approach)

Additional context

N/A