uncouple Env from Vapor and Particle Classes

[Gorkowski]

Uncouple the Env. Class from its inheritances. This will not directly remove those subclasses but we build these same capabilities in a new method. If we like it that way, then we can delete the old particle class.

[Gorkowski]

@ngmahfouz This pylance type error is what I see: Argument of type "PlainQuantity[Any]" cannot be assigned to parameter "density" of type "int" in function "mass"   "PlainQuantity[Any]" is incompatible with "int"

under particle instance method (but shows up in most methods that use pint.units) def particle_mass(self): """ Returns mass of particle. """ return mass( radius=self.particle_radius, density=self.particle_density, shape_factor=self.shape_factor, volume_void=self.volume_void, )

[github-actions[bot]]

This will be closed soon due to inactivity