Grid component: Expressions to hide entire rows/columns/cells

[olemartinorg]

Description

In #107, it's mentioned that it should be possible to hide rows/cells/columns in table components. This seems most applicable and useful to the Grid component. That mention has been extracted to this issue.

It should be possble to put these expressions on both a row and cell configuration, possibly also with an expression on the cell-level on the first cell in the table where it is possible to hide an entire column.

Make sure that:

• Hiding a row/column/cell also hides the component(s) within them. Expressions looking up the ["component", ...] value for a hidden component should return null even if the component has data in the data model.
• If colSpan and rowSpan has been implemented, hidden rows/columns hide the rows/columns they span over, and possibly inversely, are spanned by. This could get complicated, so take shortcuts where needed - but document them.

Additional Information

• Design: Tables #107
• New component: Grid #583
• Grid/rowsBefore/rowsAfter: Støtte for å slå sammen celler (colSpan/rowSpan) #1187