merge for v0.5

[raphaelquast]

This release marks the first stable version of the rt1_model package!

🌦️ Changes

Note

There have been major changes for method-names compared to v0.4 in order to make the API more clear!
All changes primarily affect internals and should not interfere with code that only evaluates the model!
(e.g. code in the example-notebooks remains unchanged etc.)

• SurfaceScatter and VolumeScatter are now abstract base classes for scattering functions
• Scatter-objects now define an explicit symbolic version of the scattering angle X.scattering_angle_symbolic
• ❗ The following methods and properties have been re-named
  • X.legcoefs -> X.legendre_coefficients
  • X.scat_angle_symbolic -> X.scattering_angle_symbolic
  • X._func -> X.phase_function
  • X.scat_angle() -> X.calc_scattering_angle()
  • X.legexpansion() -> X.legendre_expansion()

🔨 Fixes

• allow passing kwargs to R.surface(), R.volume() and R.interaction()
• fix clearing geometry cache
• fix treatment of scalar input values when evaluating the interaction term
• remove repeated definitions for symbolic scattering angles
• remove obsolete check for existance of _ncoefs property
• use random seeds to make notebook-based tests reproducible