ROS2 Action Clients

[stonier]

Action Client Behaviour

• basic behaviour, #83
• handle rejections on acceptance, #84
• handle result failures, #84

Tests

• mock action server, #83
• goal acceptance, #83
• goal rejection, #84
• execution to success, #83
• execution to failure, #84
• pre-eemption (no need, the behaviour is not designed to preempt, just send and cancel)
• cancelling, #83