Changes:
 - The grouping strategy for sharded data has been improved
 - The number of BAM files per sample is calculated by grouping the sample by ID after splitting the FASTQ files, then counting the total number of FASTQ files created.
 - This has to wait for all FASTQ files to be produced by FASTP, but is more reliable.
 - After alignment, the number of FASTQ files is used to wait to determine the expected number of BAM files used by groupBy.

Fixes #1357

Changes:
 - FASTP uses blocks of 250 reads when splitting a FASTQ file.
 - This update makes 250 the minimum sized block to split a FASTQ file into.
 - Updates help text accordingly

Fixes #1363