filterNextflowOutput could benefit from some extra common patterns

[maxulysse]

Downloading plugin
Staging foreign file

[agrima2010]

nf-test failing due to different snapshots - WARN: Singularity cache directory has not been defined -- Remote image will be stored in the path: /workspaces/seqinspector/.nf-test/tests/95e103e9afe04b20343bc828573cead3/work/singularity -- Use the environment variable NXF_SINGULARITY_CACHEDIR to specify a different location