Stability Margin with Compressibility Factor

[giovaniceotto]

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

Currently, the Flight class has a property named Flight.staticMargin, which returns the static margin as a function of time. However, since it is the static margin, it always assumes Mach=0.0, and, thus, the Prandtl-Glauert compressibility correction factor $beta$ is always 1.

Describe the solution you'd like

For the Rocket class:

• Rocket.initialStabilityMargin(mach): a method which computes the initial stability margin given a Mach number.

For the Flight class:

• Flight.stabilityMargin(): a property which returns the stability margin, as a Function of time, for the entire flight, accounting for Mach numbers different from 0, and changing center of mass position.

Additional context

This is a common request from OpenRocket users.

[Gui-FernandesBR]

Hey, this is a common request from RocketPy users, let's increase this priority right after release v1.0.0

Please @MateusStano 👨‍💻

FYI,

[Gui-FernandesBR]

Seems like the issue statement was solved by the #377
We still have some enhancements to do regarding the stability margin, tho.