Ensure compatible QoS in ros2 subscriptions

[pepisg]

This PR implements a function to get the QoS with which topics are being published, and then uses that function to subscribe to topics using the same QoS. This aims to avoid incompatibilities when subscribing in ROS2.

This aims to solve #93

[nakai-omer]

Please merge this

EDIT:
I am getting the following error trying to run this, using humble:

[rosboard_node-27] AttributeError: 'Subscriber' object has no attribute '_sub'
[rosboard_node-27] [INFO] [1658420978.174763043] [rosboard_node]: Subscribing to /map
[rosboard_node-27]
[rosboard_node-27] >>> [rcutils|error_handling.c:108] rcutils_set_error_state()
[rosboard_node-27] This error state is being overwritten:
[rosboard_node-27]
[rosboard_node-27] 'Unknown QoS history policy, at ./src/qos.cpp:61'
[rosboard_node-27]
[rosboard_node-27] with this new error message:
[rosboard_node-27]
[rosboard_node-27] 'create_publisher() failed setting topic QoS, at ./src/subscription.cpp:223'

[HX2003]

I added the following in rosboard/rosboard.py after line 135 and it works.

                if(topic_info[0].qos_profile.history == HistoryPolicy.UNKNOWN):
                    topic_info[0].qos_profile.history = HistoryPolicy.KEEP_LAST  

[dheera]

Thank you!