Command to recreate per lane bam from a merged bam

Refer to AT-658, this command tool is needed to recreate per lane bam from a merged bam. The steps involved are: extract read group bam, compare flagstat, revert markdup tag, reheader bam, create bam index, create bam md5, move outputs over.
It actually makes the per lane bam with the use of G::M::T::Sam::ExtractReadGroup. This command is to recreate per lane bam (from merged bam). My previous comment also describes this.