Fix/system issues from parameter studies

Fix issues discovered in systems_design through parameter studies

Description

Fixes several small issues discovered through the parameter studies:

1. systems_design uses the landing gear mass from the acxml to calculate the power requirement of the landing gear actuation. When this mass is not available, systems design estimates a landing gear mass but that is not written to any output. Thus, the scaling factor in the config was unnecessary. It is removed and comments are added to the code to clarify this.
2. the variable hydraulic pressure and a related function are removed since these are not used. Thus, changing the hydraulic pressure had no effect.
3. corrects the switch for using a default actuator in the flight control systems. It is now read correctly and can be used.
4. boundaries are added in the config for efficiency factors and the parameters of relative maximum power since these only work in certain ranges.
5. remove unused parameter "heat_per_light_length"
6. "off_on_takeoff" switch of the ECS was not doing anything because the corresponding mission step names were incorrect in the code. These are now corrected.
7. Avionics bay location was not set/changed correctly according to config settings because the payload tube reference point was wrong. Reading of this point is now fixed.
8. The wrong wing reference point was used to calculate the system center of gravity (for those systems that reference their CoG to the wing). Because of that the CoG of the systems was too forward. Fixing this issue moves the system CoG considerably backward. @Moritz.barnert @Florian.Schueltke we should discuss if this is correct now.

Related Issue(s)

• Fixes issues discovered in parameter studies of systems_design (Issue#130)

Screenshots/Logs

N.A.

Testing Instructions

1. Change the following config settings and check if you get the expected result:

2. Check if the systems CoG now behaves as expected in the workflow.

Developer Checklist

• Code has been tested locally and/or in pipeline.
• Merge conflicts resolved with the target branch.