burrows-wheeler approximate match by utilizing pigeonhole principle. does not work correctly.
added helper function for pattern segmentation into equal length blocks (apply exact matching with).
alternative method at solving the approximate match problem by using text indexing of k-mer length. limited by set pattern length.
final attempt at approximate match problem. method does not involve burrows-wheeler. simply searches text for exact match locations to the segmented pattern substrings and extend match to check for hamming distance for entire pattern length.