Fix column counts, missing icons, tiles in expandable tile mode
- Dynamic column equation did not seem to work at various resolutions as planned, refactor to use a more known approach of providing the column count at >=x resolution to get the expected result
- Replace and go back to using PlasmaCore.IconItems as using Kirigami Icons results in missing or corrupted icons and QPainter throws up some errors
- Additional fixes for layout when expandable tile mode and compact delegates are active