Create nf-test for STARFUSION_DETECT using a junction file as input

[rannick]

Description of feature

STAR-Fusion handles 2 modes,
i) the alignment self-contained: input to STAR-Fusion is fastq files
ii) alignment executed prior to STAR-Fusion execution: input to STAR-Fusion is the junction file
Both should be tested. ii is the way the pipeline works