Add rownames/set IDs to output of `setData()`

[robertamezquita]

Current implementation does not have the set IDs corresponding to setData() out.

gmt_file <- system.file(package="unisets", "extdata", "example.gmt")
base_sets_from_gmt <- import(gmt_file)
setData(base_sets_from_gmt)

IdVector of length 4 with 4 unique identifiers
Ids: HALLMARK_TNFA_SIGNALING_VIA_NFKB, HALLMARK_HYPOXIA, HALLMARK_CHOLESTEROL_HOMEOSTASIS, HALLMARK_MITOTIC_SPINDLE
Metadata: source (1 column)

elementMetadata(setData(base_sets_from_gmt))

DataFrame with 4 rows and 1 column
                                                                            source
                                                                       <character>
1 http://www.broadinstitute.org/gsea/msigdb/cards/HALLMARK_TNFA_SIGNALING_VIA_NFKB
2                 http://www.broadinstitute.org/gsea/msigdb/cards/HALLMARK_HYPOXIA
3 http://www.broadinstitute.org/gsea/msigdb/cards/HALLMARK_CHOLESTEROL_HOMEOSTASIS
4         http://www.broadinstitute.org/gsea/msigdb/cards/HALLMARK_MITOTIC_SPINDLE