This aligns the behavior of params_yaml with params_config library so that
when a mapping is read using getlist it returns the number of elements in
the mapping instead of 0.
This commit introduces a substitute module library for setting up softmodems using YAML instead of libconfig.
The softmodems should work the same with both types of files. Extra care was put to make sure the behavior
of both modules is the same.
Example yaml config files were added for the UE and gNB