177 valgrind memcheck

This branch contains the fixes for the memory leaks induced by PETSc wrappers and lua functions as well as the CI test to make sure that these do not produce memory leaks for future contributions. Additionally, all the models stemming from ModelInstances are also tested for memory leaks. This CI test is done using Valgrind and has been added to the Analysis stage and as it is fairly long (around 1h40mn), it is triggered only when the rest of the analysis pipeline is also on.