multiqc: add v1.7

src/docker_modules/multiqc/1.7/Dockerfile

src/docker_modules/multiqc/1.7/docker_init.sh

src/nf_modules/multiqc/multiqc_paired.config

src/nf_modules/multiqc/multiqc_single.config

src/singularity_modules/multiqc/1.7/build.sh

src/singularity_modules/multiqc/1.7/multiqc.def