(int, optional) The number of digits after the decimal
separator to round to.
thousands_separator
(string, optional) Used as mark between every 3
decimals before the decimal point.
decimal_separator
(string, optional) The character to be used to
indicate the numeric decimal point.
lower_indicator
(Boolaen, optional, default = TRUE) If the result is
(since it is rounded) zero: Should there be displayed a lower-indicator?
E.g. DIZtools::robust_round(0.00001) results internally in "0.00".
The more intuitive result therefore would be "<0.01", which can be enabled
using the parameter `lower_indicator == TRUE`.