Add new functions and constants to Bigdecimal:
Bigdecimal.one represents the value one in the Bigdecimal typediv: computes the division of two Bigdecimal values with optional decimals_precision parameter (default 15)sqrt: computes the square root of a Bigdecimal value with optional decimals_precision parameter (default 15)**: computes the power of a Bigdecimal value raised to a non-negative integer exponentscale_int: scales a Bigdecimal value by an integer factoris_integral: returns true if and only if the input value is an integerround_to_power_of_ten: rounds the given value to the nearest power of ten with optional rounding direction parameterto_bigint_exact: converts the given value to an exact Bigint.t if it is an integral value; returns None otherwiseto_bigint_exact_exn: converts the given value to an exact Bigint.t if it is an integral value; raises an exception otherwiselog10_int_exact: calculates the log in base 10; returns Option.None if the result is not representable as an integer