fix(transformTFIDF): don't transpose result

[jamespeapen]

Return a non transposed matrix since the transformTFIDF output currently need to be transposed again.

From the vignette (https://huishenlab.github.io/compartmap/articles/compartmap.html#running-the-compartmap-workflow):

# TF-IDF transform the signals
k562_scrna_chr14_tfidf <- transformTFIDF(assay(k562_scrna_se_chr14))

# Add back the TF-IDF counts to the object in the counts slot
assay(k562_scrna_se_chr14, "counts") <- t(k562_scrna_chr14_tfidf)

Are there any conditions where the function needs to return a transposed matrix?