fasterq-dump => disk: local-ssd

### Description of feature As far as I can tell, the [fasterqdump module](https://github.com/nf-core/modules/blob/master/modules/nf-core/sratools/fasterqdump/main.nf) does not set [disk](https://www.nextflow.io/docs/latest/reference/process.html#disk). Setting the disk to `local-ssd` for use with `google-batch` could be quite helpful for speeding up the writing of temp files ([docs](https://www.nextflow.io/docs/latest/google.html#process-definition)). More generally, if `disk` is not set (and dynamically expanded for large SRA files), what would prevent the job from running out of disk space -- at least for cloud jobs?