Bug 1611682 - Fix show DOM properties. r=rcaliman.

This patch work around the fact that the `inspect` command
is used for different purpose:
- open the evaluated element in the inspector/debugger
- expand a given object in the console

In order to do that, a second parameter is added to indicate
which usage we do want.
This is not pretty, but I can't see something as straightforward
to fix this issue.
Given that there's plan to have a properties sidebar in the
inspector, it might be enough for now.

The existing test is modified to check that the object is indeed
expanded in the console.

Differential Revision: https://phabricator.services.mozilla.com/D61662

devtools/client/inspector/markup/markup-context-menu.js

@@ -345,7 +345,7 @@ class MarkupContextMenu {
   _showDOMProperties() {
     this.toolbox.openSplitConsole().then(() => {
       const { hud } = this.toolbox.getPanel("webconsole");
-      hud.ui.wrapper.dispatchEvaluateExpression("inspect($0)");
+      hud.ui.wrapper.dispatchEvaluateExpression("inspect($0, true)");
     });
   }