Ext.grid.filters.filter.List: option to select/deselect all

[fabriciomurta]

Ext.NET forum thread: ListFilter -- select all option Requested when 5.2.0 was the current Ext.NET release.

The feature here consists in having some means to toggle whole-selection in the list of items of the Grid Panel's GridFilters plugin when the type is List. Could be a "header-like" checkbox or something intuitive enough to switch selection between all and none.

This would be especially useful if the list is reasonably long and the user wants to select all, except a given subset of entries, instead of having to select almost all options one by one.

This feature is used in the Grid Panel > Plugins > Grid Filters Local example.