Generic function
Finds an item in a list control or a table control.
find-item list-or-table object #key => found-item
type-union
(<list-control>, <table-control>).
<object>.
type-union(<list-item>, <table-item>, #f).
duim-gadgets
duim-gadgets
Finds the item in a list control or a table control that corresponds to object.
make-item, page 609
remove-item, page 636