Bug 1424162: Put the filter bar before the console output in the web console. r=nchevobbe

The filter bar was already positioned before the console output visually.
However, accessibility clients such as screen readers rely on the semantic order, not the visual order, for positioning of content.
This makes it easier for screen reader users to quickly get to the bottom of the console output, which is important for efficiency when reading recent output.

MozReview-Commit-ID: Ae8z6H1k9np

--HG--
extra : rebase_source : 9a5a6cd3db4b5398e6e0f2a648721849e7c0fb78

devtools/client/webconsole/new-console-output/new-console-output-wrapper.js

@@ -211,8 +211,8 @@ NewConsoleOutputWrapper.prototype = {
         { store },
         dom.div(
           {className: "webconsole-output-wrapper"},
-          consoleOutput,
           filterBar,
+          consoleOutput,
           sideBar
         ));
       this.body = ReactDOM.render(provider, this.parentNode);