Fix bug SDK-19480 Horizontal gaps can become nonzero when explicitly set to 0,
SDK-19233 Increasing the width of the content (e.g. columnWidth or horizontalGap) eventually causes a Group to unnecessarily increase its height,
SDK-19519 TileLayout justifyColumns and justifyRows should use classes with static constant
Fix: SDK-19480: Make sure that we enforce the maximum rounded cell width/height instead of the original value.
Fix: SDK-19233: Make sure there are no empty rows/columns, check for both top and bottom rounding for both rows and columns.
QE Notes: None
Doc Notes: None
Bugs: SDK-19480, SDK-19233
tests: checkintests, gen docs, mustella (tileLayout)