This list is pretty awesome:

<img width="390" alt="Screenshot 2020-04-03 at 00 12 08" src="https://user-images.githubusercontent.com/810438/78308234-e0047780-753f-11ea-9d4f-1e2d31e5baa0.png">

But always struggle to guess which component in the owner list I need to jump to.

We should make hovering the owner list highlight components, just like the main tree view does.

@hristo-kanchev, interested?
┆ ••<Foobar>           ┆
   ┆ ••••<Baz>            ┆
   ┗┛
 In xtrm cass this diffrc can b important:
   ┏┓
   ┆ <RallyLongNam>     ┆
   ┆ ••<Foo>              ┆
   ┆ ••••<Bar>            ┆
   ┆ ••••••<Baz>          ┆
   ┆ ••••••••<Qux>        ┆
   ┗┛
 In th a,
m
 w
   ┏┓
   ┆ <RallyLongNam>     ┆
   ┆ •<Foo>               ┆
   ┆ ••<Bar>              ┆
   ┆ •••<Baz>             ┆
   ┆ ••••<Qux>            ┆
   ┗┛
  can fit ach child,
 giv th child's fixd width and dpth within th tr.
 s indtation sizs...
function updatIndtationSizVar(
  innrDiv: HTMLDivElmt,
  cachdChildWidths: WakMap<HTMLElmt, numbr>,
  indtationSizRf: {|currt: numbr|},
  prvListWidthRf: {|currt: numbr|},
): void {