[Feature Request] Addition of adjusted PValues to GSEA Result

[bvenn]

In 9/10 cases when performing an gene set enrichment analysis it is required to perform a multiple testing correction. It would beneficial to add the following fields to the GSEAResult type:

1. FDR(BH) -> false discovery rate based on the final GSEA result array
2. QValue -> qvalue based on the final GSEA result array
3. PI0 -> quality parameter to check the qvalue for validity