[AeroUtils] Updated AeroUtils library with other functions

Implemented functions in the AeroUtils library:

• computeRho for calculating the air density at a given altitude;
• computeSoundSpeed for calculating the speed of sound at a given altitude;
• computeMach for calculating the mach given speed and altitude;

All heights are agl (above-ground-level) and the t0 is the temperature (in Kelvin) at height 0m agl. If we consider msl altitudes, the t0 to be passed is the MSL_TEMPERATURE that is 288.15 K.