Simplify branching logic regarding different mission methods in internal Aviary code

[johnjasa]

Desired capability or behavior.

Purposefully move some of the separating distinctions between the different mission methods, specifically in methods_for_level2, and move these distinctions to lower in the call tree. Promote variables to the same name where it makes sense; the first part of this task if to figure out which items or logical branches can be unified. This is not only for the mission methods but for pre-mission as well. Really zoom into the ODE and EOM level even and try to unify that

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

No response

Associated Bug Report

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