Update to inputs for the pressure drop calculation

[PoggeyWinter]

Is your feature request related to a problem? Please describe.
Update to inputs for the pressure drop calculation:

1. Friction factor calculation
2. Rules for mass flowrate

Describe the solution you'd like

1. Current friction factor calculation is to be updated to the "Swamee-Jain" explicit approximation:

f= 0.25/([log((ε/3.7D)+(5.74/(Re^0.7)))]^2)

f= friction factor
D= Diameter (m)
Re= Reynolds number
ε= roughness (m) (this will be provided as part of a model definition, but a value of 4.50E-05 can be used as a placeholder for a steel pipe)

Note on accuracy: The approximation from this equation can vary by 2.8% within its applicable range:

• Reynolds number between 5000 and 3E+8
• Relative Roughness (ε/D) between 1E-6 and 0.01

2. Mass flowrate will remain conserved throughout the model, initially set by user input.

• Mass flowrate can be split between multiple lines as in the example of the "splitter" object, where the flowrate input to the object is equal to the sum of the output flowrates from the object.

[Jerell]

I need some values to use in tests. I updated the function and the end pressure for a pipe segment is 5x higher.