Copter: add battery and sensors to iris

[srmainwaring]

Add simple battery model and additional sensors to the Iris.

Details

• Add battery plugin.
• Add air_pressure
• Add magnetometer
• Add navsat

Tests

Example showing battery message mapped from Gazebo through to ROS 2.

$ ros2 topic echo /battery
---
header:
  stamp:
    sec: 222
    nanosec: 324000000
  frame_id: ''
voltage: 12.061639785766602
temperature: 0.0
current: 16.57807731628418
charge: 4.003036975860596
capacity: 5.0
design_capacity: .nan
percentage: 80.06074523925781
power_supply_status: 2
power_supply_health: 0
power_supply_technology: 0
present: true
cell_voltage: []
cell_temperature: []
location: ''
serial_number: ''
---