Create a drone status/health package that monitors a custom state of the drone

[AlexanderWangY]

This package should be publishing to a /drone/status or /drone/health topic and have a custom message

This message should include

mode = ?
armed?
imu ok?
gps ok?
etc etc (up to you tbh)

Also expose a service that allows us to fetch the current status as needed (for any nodes that will need that in the future)

Test this by analyzing outputs by ros echoing the topic and also rosservice calling the service node.

This package is needed so later packages have an easy abstracted way to fetch the status of the drone system in case of emergencies or other conditionals. (For example, mode != LAND if you want to takeoff)

[AlexanderWangY]

There also should already be a DroneHealth msg in the common_msgs