Absolute actuators not correctly ignored in position save file

[JosephBowkett]

As discovered by Arthur B, starting and stopping a casah/ros2/fcat node with only absolute platinum actuators causes a bug where a fastcat_saved_positions.yaml file will be created, but nothing placed inside it (because there are no relative encoder actuators) and then the node fails on the next startup because the file does not contain the actuators: field.

The fix is likely to correctly check for (*device)->GetState()->something_something->absolute_encoders == false here: https://github.com/nasa-jpl/fastcat/blob/v0.12.13/src/manager.cc#L945 (paraphrased)

[JosephBowkett]

Further update, it looks like there is no absolute encoder parameter implemented for GoldActuator or PlatinumActuator

Update: I was reminded that Gold and Platinum derive from Actuator, so should still have the parameter available

[JosephBowkett]

Similar, but not quite the same as #45

[arthur-bouton]

Any update on this matter? So far, I have to delete the file fastcat_saved_positions.yaml each time I want to restart the fcat node.
Not entirely sure if this is related, but the fcat node is also outputting this warning each time it receives a new command:
fcat.cpp:251 | EVR [WARNING_HI ] Device type does not match for [actuator name]