output stage1_genome_summary.csv during target clean

[taylorreiter]

• total_bp: total_bad_bp is already reported, so this would allow us to estimate % contamination
• total_bp_ident: unless this is just total_bp * f_ident, then this column would be a useful addition. If it's just total_bp * f_ident, then it's not necessary to add it because it can be easily calculated by the user.

[taylorreiter]

contaminated_at_filter_rank: a yes/no or True/False column with this information would be handy. And make interpretation super straightforward.

[taylorreiter]

digging into charcoal more today, looks like some of this info already exists in stage1/*.genome_summary.csv:
total_contigs_bp,total_contigs_n

[taylorreiter]

ok digging more -- some of this info is in stage1_genome_summary.csv, but stage1_genome_summary.csv isn't made when I run target clean. So it would be lovely if that file could be produced for target clean.