add cosmors for reranking after geom opt

[lmseidler]

This pull request improves the handling of COSMO-RS solvent models in geometry optimizations, ensuring that when cosmors or cosmors-fine is selected, geometry optimizations are performed with dcosmors and a final reranking is done using the chosen COSMO-RS model. It also adds related configuration options, updates reranking logic, and expands test coverage for these behaviors.

COSMO-RS solvent model handling:

• Updated OptimizationConfig to support COSMORS and COSMORS_FINE as valid solvent models, added a gsolv_included option, and implemented logic to warn users and set gsolv_included to False when these models are selected. Geometry optimizations will use dcosmors, with a final reranking using the selected COSMO-RS model. [1] [2]
• In the optimization workflow, when COSMORS or COSMORS_FINE is chosen, geometry optimization is performed with dcosmors, and a final single-point calculation is run with the selected COSMO-RS model for reranking. [1] [2]

Testing improvements:

• Added tests to verify that gsolv_included is set to False and the appropriate warning is issued for COSMO-RS models, and that no warning is issued for dcosmors. Also added a test for the default value of gsolv_included. [1] [2]

Documentation and minor improvements:

• Improved docstrings for header formatting utilities h1 and h2 for clarity. [1] [2]