Extend the highlight of the current stepping line in stepping tests to all opened editors

As a Kotlin/JS developer, I find stepping tests expectations placed quite away from actual source code:

```kt
// FILE: test.kt

class A {
val prop = 1

fun foo() {
prop
}
}

fun box() {
val a = A()
a.prop
a.foo()
}

// EXPECTATIONS JVM_IR (12 lines)
...
// EXPECTATIONS NATIVE (14 lines)
...

// EXPECTATIONS JS_IR (finally!)
```

Which means I can't conveniently use yellow highlighting (I think the same for the Wasm folks whose expectations are located even deeper)

As a workaround, I've tried splitting the editor, use left one to scroll to my expectations, and the right one to the source code, something like that:

The problem with such approach is that highlighting is not synced across the opened editors, it only highlights the current editor tab and not other ones for the same file:

It would be very useful to sync the highlighting across editors to be able to use such a workaround.