Improve end to end test coverage for List View

[talldan]

The feature set of ListView has expanded quite considerably recently, and it has also become an important feature in the site editor as well as continuing to be an important feature for the accessibility of the block editor.

There is test coverage for List View as a side effect of many other tests that use if for selecting blocks, but the feature should really have better test coverage in and of itself.

Tests that I think are missing:

• A few tests for basic keyboard navigation (up, down, left, right, home, end)
• Tests for collapsing / expanding blocks
• Better drag and drop coverage (e.g. nesting blocks, dragging from list view to the canvas, dragging from the canvas to list view)
• Tests for the options menu and some of the more popular items in that menu (to catch issues like this one - 'Duplicate' blocks from "List View" throws an error. #38759)