Add support for sum of truncated values

[benedeki]

Background

Floating-point numbers no always have exact representation, so a rounding error can be introduced when summing up floating-point numbers.

In order to control accuracy and completeness of such numbers it makes sense to truncate the fractional part, summing up only the integral part of numbers, which have exact representation.

Feature

Add support for sum of truncated values.

P.S.
Update the documentation with new function.

Proposed solusion

Type	Description
controlType.aggregatedTruncTotal	Calculates SUM(TRUNC()) of the specified column
controlType.absAggregatedTruncTotal	Calculates SUM(TRUNC(ABS())) of the specified column

SUM(TRUNC(x)) - Sum of truncated numbers of a column x.
SUM(TRUNC(ABS(x)) - Sum of truncated absolute values numbers of a column x.

Examples

• trunc(123) = 123
• trunc(123.0001) = 123
• trunc(123.456) = 123
• trunc(123.999) = 123
• trunc(-123.456) = -123
• trunc(-123.999) = -123

NB! Solution

This is a copy of recent Atum feature. Please copy the solution from there.
Issue: Atum/#156
PR: Atum/#157