UI: remove explicit column handling in ListModel
TESTS: fileview: introduce ListStore and ListModelBinding
UI: factory: introduce create_ui_child and parent-local namespace handling
UI: listarea: fix child creation
UI: listarea: fix XML references to list model
TESTS: fileview: set list fields to a simple single string for now
UI: listarea: rewrite resize_scroll() with a number of cleanups
UI: listarea: method rename for disambiguation
TESTS: start row numbering from 0
UI: listarea: rewrite row positioning for virtual scrolling, cache row heights
UI: listarea: clip rendered list rows to list area
UI: listarea: draw list rows with base background color
UI: use brighter colors for list row even/odd coloring and selection
TESTS: fileview: produce alternating row heights
UI: listarea: fix up positioning near the edges
UI: listarea: process model updates
TESTS: added test model to show case virtual scrolling for unequal rows
UI: listarea: removed old test model code
UI: listarea: fix signal disconnection
UI: listarea: split implementation into vscroll and pscroll variants