Optimization and internal improvements

Features:
Added the ability to select the shift of the calculated bar relative to the current one.
Thus, the indicator can now display not only the change of the last closed bar, but also any other, including the current one.

Fixed:
Fixed an error of incorrect calculation of negative values that occurred in some cases.

P.S. Thank you all for your feedback, it helps me to improve the products!
If you notice any bugs / have any ideas for improvement - please let me know via direct message.