This function is called at each iteration of the constant data removal process until no constant data remains.
perform_remove_constants(data, cutoff)A <list> with the input dataset where all empty rows and
columns as well as constant columns have been removed.
The input <data.frame> or <linelist>
A <numeric> value specifying the cut-off for removing
constant data. The possible values vary between 0 (excluded) and 1
(included). The default is 1 i.e. remove rows and columns with 100%
constant data.