Read alignment beams configurations from file for the fit

[bregeon]

• alignment beams configurations should be available in a parquet file
• implement a way to load some of them during the fitting procedure
• should handle the case where beam configurations are used iteratively set by set

[bregeon]

somewhat par of #57

[bregeon]

• Configurations are created by hand in LSST_CCOB_ghosts_reference_beams.ipynb notebook and saved to parquet file, e.g. data/ghosts_reference_beam_configurations.parquet.
• In the fitting script, beam configurations are read from the parquet file and converted to a beam set to be passed to the ghosts_fit constructor

[bregeon]

• ghosts_fit.run now has two more running modes "iterate_beam_sets" and "iterate_beam_sets_and_optics"