Add IO support #198

[mhubii]

To do:

• Add io configurations to lbr_system_config.yaml
• Parse io configurations via lbr_system_interface.xacro to system_interface.hpp
• Add new type values to system_interface_type_values.hpp
• Add io to IDL https://github.com/lbr-stack/lbr_fri_idl and create releases for older versions of this stack
• Add io read / write to lbr_fri_ros2 interfaces
• Check IO support for different FRI versions (add pre-processor directives where unsupported, e.g. FRI 1.11)

Other considerations:

• How does this fit into the bigger picture of dynamically loading the FRI at runtime (to support rosdistro)?