Update karibu-testing to support LitRenderer

[vlipovetskii]

No description provided.

[mvysny]

Karibu-Testing currently does have a simple support for LitRenderers: for example:

LitRenderer.of<Int>("<div>\${item.foo}</div>")
                    .withProperty("foo") { "Item #$it" }

is rendered as Item #25 (for an integer row value of '25').

This is a good balance between Karibu not supporting LitRenderers at all, and dumping all of the HTML, making the Grid tests too chatty and bloated.

However, if you'd like to have this algorithm changed, please list a counter-example where this simple algorithm doesn't do a good job.