Improvements in Modkit, Multiqc and Merge_QC_REPORT for traceability and robustness.

 Path: Standardized output paths using parentheses.
 MAKE_QC_REPORT: Adjusted publishDir to output all files into a single   folder.
 MERGE_QC_REPORT: Updated publishDir and output to use pattern "*.tsv"  for clearer file specification.
 Script: Added `set -euo pipefail` to MAKE_QC_REPORT and  MERGE_QC_REPORT to ensure immediate abortion on error.
 Modkit: Updated output file names to reflect meaningful identifiers.