Installation: downloading required databases

Add scripts and rules to download and setup the required databases.

Q: main workflow or sub-workflow?

• trimmomatic adapters
• sortmerna's rRNA gene sequences
• reference genome for PhiX
• HMMs for annotation (mantis)
• kraken2 database(s)
• GTDBtk data
• mantis databases setup

Include scripts provided by @pedro.queiros: IMP_autodl.tar.xz