src/db_utils/frequency_scripts/create_n_fill_exon_frequency_file.py: fix...

src/db_utils/frequency_scripts/create_n_fill_exon_frequency_file.py: fix multiprocess_freq_orf and compute_gene_orf_data function (rename the column new_freq to frequency) + fix of create_or_load_freq_table (concatenation of wrong tables to create the final gene frequency table) + columns adjustement in fill_frequency_tables