initial_sizing: calculate fuel mass with MTOM-OME-PL

TODO

Summary

As discussed in https://git.rwth-aachen.de/unicado/unicado-package/-/issues/46, tank_design currently includes an initial fuel/energy estimation whereas this should be done by initial_sizing.

Subtasks

• calculate the fuel/energy mass based on MTOM-OME-PL
• save in the acXML
• delete estimation in tank_design