MoveItPy only supports a single set of parameters

[henningkayser]

Description

MoveItPy parses the --param-file arg at constructions here, ignoring that there can be multiple.
This is the case when multiple dictionaries are listed as launch parameters, as for example here with RViz.

I ran into this when trying to pass use_sim_time:=true to moveit_py which always failed, even though MoveGroup/MoveItCpp didn't have any issues with that. The additional parameters where simply ignored. Side note, the temporary parameter files are being added to /tmp/, the actual file names are listed in the ROS log.

Your environment

• ROS Distro: Humble
• OS Version: Ubuntu 22.04
• jammy-humble binaries (main branch)

Steps to reproduce

Add {use_sim_time:=True} to the moveit_py parameters, then query ros2 param get moveit_py use_sim_time (it's False).

Expected behaviour

All passed parameters should be forwarded to MoveItCpp.

Actual behaviour

All parameters that are not in the first dict are ignored by moveit_py.