Add raw data table output

[RaverJay]

• implements Summary report also in text table format #88
• always adds a .csv and a .xlsx data table to the poreCov output
• columns:
  sample | kraken2_numreads_sarscov2 | kraken2_numreads_human | kraken2_numreads_unclassified | kraken2_numreads_total | president_identity | president_mismatches | president_percentN | president_numN | president_QC_pass | pangolin_lineage | pangolin_probability | nextclade_clade | nextclade_mutations | nextclade_deletions
• sample:
  poreCov_summary_report_2021-03-26--16-25-44_datatable.xlsx
• new fastcov container (added openpyxl package)

[hoelzer]

@RaverJay awesome! really helpful.

I can approve this PR.

Just a minor suggestion: what do you guys think about a TSV instead of a CSV? E.g. the nextclade_mutations column has also , and if I e.g. parse the current csv w/ e.g. awk I will run into problems. A proper \tab separation might be safer because we don't run into issues with , being part of any output strings.

[replikation]

@hoelzer @RaverJay yep tab separated is better/saver than csv

[replikation]

@RaverJay added tsv to your script.