Grid Calculation: Allow use of property value for destination case if no input case is available

[magnesj]

Workflow description

1. create a property for all cells using an expression like my_expr := 1
2. create a property defined by expressiont seconde := 2 for visible cells, set all other cells to the property value of my_expr
3. the content of Property Variable Name is not populated with available properties for the destination case

Error dialog not possible to close

If an invalid name is given for Property Variable Name, a error message is displayed. This dialog is immediately displayed again when closed, causing an eternal loop.

New solution to select result

Related to #10986