KoopmansWorkChain cannot submit workchains, only run

[mikibonacci]

This is due to the fact that we are submitting workchains on the fly, without providing the information on the KoopmansWorkChain.

so we cannot call self.submit(), but only submit(). This is not allowed if we submit the KoopmansWorkChain.

An idea could be to pass the self (i.e. the KoopmansWorkChain instance) to the ._run() in the self.run_process.

However, this implies a small additional piece of code in koopmans