Rename Mission.Constraints.MAX_MACH to Aircraft.design.MAX_MACH

[cmbenne3]

Desired capability or behavior.

This variable is actually used in aviary as an aircraft design variable and so should be renamed to Aircraft.Design.MAX_MACH.

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

No response

Associated Bug Report

No response

[jkirk5]

Description should be updated to reflect what it is used to actually calculate (which subsystems use it, if it is used to compute only one or two specific variables, list them)