bwa-mem2 support

bwa-mem2 is 1.7-2 times faster with ~2 times more memory. For time-critical data bwa-mem2 should be used.

bwa-mem2 command (CLI) seems to be compatible to bwa-mem. Therefore,

* Change binary name and module load
* Adapt conda environment
* Is there anything necessary except for the path to the FASTA for working with bwa-mem2 reference genomes?