[Filtering] ListItemView can use customized ListItem renderer

[lukas-vlcek]

List item can contain more than just a plain text. It can contain also icons, nested HTML elements (for example with highlighting). This feature adds option to implement and use custom renderer for each list.

Since the content of individual list items can be driven by data requests from REST server a special care needs to be taken when using HTML from external sources to avoid XSS attacks.

[lukas-vlcek]

More detailed docs can be found in relevant readme. Especially, new ListItemRenderer interface and new renderer option in lists configuration of ListController.