Add option to write fragment level quant

[ammarcsj]

This PR adds the option to write to disk a matrix with fragment-level quantities which can be used for detailed inspection of the data or downstream quantification algorithms.

Changes:

• Extended SearchPlanOutput.build_lfq_tables() to support fragment-level table export. When enabled, the feature exports the precursor-level group_intensity_df containing all fragments that pass the precursor level correlation filters
• Added boolean config option in config_dict["search_output"]["fragment_quant_matrix"] (default: false)
• Updated default config.yaml to include the new option