Fix wrong guideline values shown during dragging
Created by: yamgent
I investigated #35010 (closed) and found out that it was due to some floating-point errors. If I force the values to be printed as decimals, the errors become apparent:
This is due to how the offsets were calculated (some conversion from the mouse's position to the viewport's point of view). Hence different zoom levels may have different missing offsets, in fact some zoom levels seemingly do not exhibit this bug at all.
Fixed #35010 (closed) by just rounding up the numbers before printing.