Update Aviary engine deck format with optional delineation of dependent and independent variables

[jkirk5]

Desired capability or behavior.

Support the addition of a blank column in-between independent and dependent variables to allow users to communicate which variables their specific engine supports. If the blank column isn't provided, assume the default independent variables (Mach, alt, throttle)

The code to actually generate the interpolators will need to be updated in engine_deck.py with this updated format - this is also a good place to start using the interpolator builder utils that are available for aero (they dynamically create an interpolator object based on provided independent and dependent variable data)

Is your feature request related to a problem? Please describe.

No response

Associated Bug Report

No response

[jkirk5]

After further discussion with team, the blank column may be replaced with specifying variable type through the header, or a second row of headers