LT-15258: DetailsView: load Complex and Variant Forms

Add Unit tests

Change-Id: If39e512739b7646dfeb150903f3aa80a40a759ad
LT-15258: Details View: Custom Lists

Check items by default
Preserve order regardless of check state

Change-Id: I4e87e2ac2e3f16ce702fdf20a93868d71b6e4971