2D simulation prescribed flow with isotopes

[AgnieszkaZaba]

• move Szumowski to utils?
• cite Kessler '69, ('95 ?)
• docsting from Arabas '25
• unit tests for fractionation method (dm_dt and taus as inputs)
• unit test coupling condensation with isotopic fractionation with a plot having "remaining water" as x axis and delta as y axis
• add 3 new field for MPDATA advection (initial values as parameters) - add example using isotopes with the kinematic 2d env #1630
  

  PySDM/examples/PySDM_examples/Szumowski_et_al_1998/simulation.py

  Lines 70 to 73 in 7251fb1

  	initial_profiles = {
  	"th": self.settings.initial_dry_potential_temperature_profile,
  	"water_vapour_mixing_ratio": self.settings.initial_vapour_mixing_ratio_profile,
  	}

• introduce new attribute: "pre condensation water mass"
• merge physics.isotope_relaxation_timescale and physics.isotope_ratio_evolution into physics.isotope_dynamics (?)
• implement formulae for dm'/dt
• implement dynamics for number of moles (using new mass - old mass and dm'/dt)
  

  PySDM/PySDM/backends/impl_numba/methods/isotope_methods.py

  Lines 27 to 28 in 7251fb1

  	def isotopic_fractionation(self):
  	pass

• couple particle isotopic dynamics with ambient air isotopic dynamics
  

  PySDM/PySDM/particulator.py

  Lines 441 to 444 in 7251fb1

  	def isotopic_fractionation(self, heavy_isotopes: tuple):
  	self.backend.isotopic_fractionation()
  	for isotope in heavy_isotopes:
  	self.attributes.mark_updated(f"moles_{isotope}")

[AgnieszkaZaba]

Add isotopes to simulation is in this PR: #1630