getSGFeatureCountsPerSample: Compatible fragment counts for splice graph features
In ldg21/SGSeq: Splice event prediction and quantification from RNA-seq data

Obtain counts of compatible fragments for splice graph features.

1 2	getSGFeatureCountsPerSample(features, file_bam, paired_end, sample_name, min_anchor, retain_coverage, verbose, cores)

`features`	`SGFeatures` object
`file_bam`	BAM file with genomic RNA-seq read alignments
`paired_end`	Logical, `TRUE` for paired-end data, `FALSE` for single-end data
`sample_name`	Sample name used in messages
`min_anchor`	Integer specifiying minimum anchor length
`retain_coverage`	Logical indicating whether coverage for each exon should be retained as an `RleList` in metadata column “coverage”. This allows filtering of features using more stringent criteria after the initial prediction.
`verbose`	If `TRUE`, generate messages indicating progress
`cores`	Number of cores available for parallel processing