Modifying KoResourceItemChooser and View to support Strip item view widgets in Krita

KoResourceItemView only offered the option to have a fixed amount of columns in the display, there was no way to fix the number of rows (for example, to make a strip widget, which is the case now). Appropriate modifications were made to allow this type of resource item view to be possible.
This commit makes the previous commit "Porting the first changes for..." not break compilation of Krita anymore.