Add optional steps to genome_submit subworkflow to handle metadata (coverm)

### Description of feature

Coverage calculation

Now current subworkflow https://github.com/nf-core/seqsubmit/blob/dev/workflows/genomesubmit.nf takes all metadata as input samplesheet. We need to allow some metadata be missing and pipeline should detect it and generate.
For example, if user didn't provide taxonomy - seqsubmit/genomesubmit should run CAT/BAT to assign taxonomy for mags/bins.