Change multiple inputs to tuples in annotate_vcf.nf

[mgeaghan]

Description of feature

Currently, in annotate_vcf.nf, the process takes multiple inputs:

Parabricks-Genomics-nf/modules/annotate_vcf.nf

Lines 7 to 12 in aca54c0

	val(cohort_name)
	path(cohort_vcf)
	path(cohort_vcf_tbi)
	val(vep_assembly)
	val(vep_species)
	path(vep_cache)

This works because the pipeline is designed to work with a single cohort, so this process should only run once. Still, it is better practice to group related inputs together as tuples. This might look like:

input:
tuple val(cohort_name), path(cohort_vcf), path(cohort_vcf_tbi)
tuple val(vep_assembly), val(vep_species), path(vep_cache)

This groups all the sample info together and groups all the VEP info together.

Note: This is a nitpick and not something we need to change right now, it's just something to keep in mind for the future.