Keeps rows with hetero >= hetero_cutoff in @GTsummary.filtered, enforces a
minimum number of rows per variant, updates @V.fitered, and rebuilds matrices and depth matrix.
Usage
filter_redeemR_by_hetero(
redeemR_obj,
hetero_cutoff,
min_cells_per_variant = 2,
QualifiedTotalCts = NULL,
filter_name = NULL
)