Use a temporary build directory for Python module output

[bjsowa]

The generate_parameter_module macro outputs the Python module to CMAKE_INSTALL_DIR during the build phase. This results in build failures on the ROS buildfarm due to permission errors (example here)

This PR modifies the macro to output the module to a temporary directory in CMAKE_CURRENT_BINARY_DIR and install it to CMAKE_INSTALL_DIR during the install phase.

[christophfroehlich]

If the current setup fails on the buildfarm, why haven't that failed earlier? Or is it that simple, nobody released a python node using this library?

[bjsowa]

If the current setup fails on the buildfarm, why haven't that failed earlier? Or is it that simple, nobody released a python node using this library?

From what I see, we are the first 😎

[christophfroehlich]

The result looks good, just not sure if there is a more cmake-native way in fixing this. So, waiting for another review.

btw: I remembered that we had an issue about python install location, but it was in setup.py configs #206.

[bjsowa]

@christophfroehlich Any chance this gets merged and released soon? I'm getting a lot of spam from ROS buildfarm about failing jobs...