kmerSimilarity: Calculate a similarity matrix based on kmers
Description
This method takes a pangenome and calculate a similarity matrix based on
cosine similarity of kmer feature vectors in an all-vs-all fashion. The
result can subsequently be used to group genes either using
graphGrouping or homebrewed grouping scheme. In case of the
latter manualGrouping should be used to add the grouping back
to the pangenome.