Enable the use of containers for running the executables

For some clusters it is necessary (and advantageous) to compile the LQCD software through a container. The dynamic linking requires that the executables are then also run through the container. BaHaMAS is supposed to allow that the executable is run through a container.

To implement this feature, slight changes in the generation of the job script have to be implemented:

• create a new global variable to specify the container command to be run and the location/name of the container
• implement a validation, that checks for a meaningful container command
• modify the lines in the job script generating function, which call the executables
• test for an empty container command for OpenQCD
• test for a meaningful container command for CL2QCD
• update the wiki pages according to the applied changes