Adding an option that allows to execute any command in a condor job

[jgalan]

Perhaps it would be better to have a dedicated python script to launch any kind of commands to condor.

I am a bit in a rush and I need this feature, I know it is not the best implementation, but just need to do it to launch the jobs I need right now.

Should be done differently.

The present PR will allow to launch any command to condor without having to use restManager --c.

For example:

python3 restManagerToCondor.py --command "ls -lrth $DUST"

Indeed I am going to use it to launch macros with restManager (but without processing config file):

python3 restManagerToCondor.py --command "restManager GenerateDataSets dataset.rml BabyIAXO_XMM_mm_Vacuum $DUST"

[jgalan]

Probably this PR doesn't need to be merged, but it gives an idea of something that could be useful to implement properly