Release 2.0.0

Changes:

• Automatic QM region selection for QM/MM.
• Job that tries to find a new reaction starting from a transition state guess only.
• Job that carries out a fast dissociation reaction trial protocol after optimizing the input structure.
• Remove scine_step_refinement job.
• Add the option allow_exhaustive_product_decomposition to jobs that carry out reaction trials, which allows products to decompose and re-optimize them until no further decomposition is observed.
• Add the option always_add_barrierless_step_for_reactive_complex to jobs that carry out reaction trials, which enables that a barrierless elementary step is added for the reactive complex formation of a bimolecular reaction irrespective of the complexation energy.
• Add option store_structures_with_frequency and store_structures_with_fraction that allow storing a portion of structures per sub-task.
• Add option spin_propensity_ts_check to scine_react_ts_guess job to specify a spin multiplicity range to be checked for the transition state different to the spin multiplicity range to be checked for the reactants and products (spin_propensity_check)
• Ensure that the calculated spin states are considered in the calculation of the dissociation energy in the DissociationCut jobs and in structure optimizing jobs (GeometryOptimization and ReactTsGuess)
• Write normalized modes in database.
• Improve dependency handling and add more typehints.
• Optimize only unique structures of the endpoints of an IRC calculation.
• Deduplicate code for analyzing both sides of the IRC part in the scine_react_job.
• Stricter conditions to distribute charges if expect_charge_separation is set to True by prohibiting changing
  already changed charge.
• Comply docstrings with numpy styling.
• Introduce Enums for ReaDuct calls.