Changes

* M2 Basic Highlighters support for highlighting elements in the page when inspecting their CSS properties and box model ([https://bugzilla.mozilla.org/show_bug.cgi?id=1623667 bug 1623667], [https://bugzilla.mozilla.org/show_bug.cgi?id=1572654 bug 1572654])* M3 Less used Highlighters: Grid, shapeAdvanced features related to highlighting elements in the page. This includes support for highlighting grid elements, shapes defined using CSS clip-pathproperty, highlighting fonts, geometry, editor for absolute positioned elements within relative positioned elements and inspecting CSS animations ([https://bugzilla.mozilla.org/show_bug.cgi?id=1568827 bug 1568827])* M3 Search within the Inspector panel doesn't included remote iframes ([https://bugzilla.mozilla.org/show_bug.cgi?id=1568880 bug 1568880])* M3 Eydropper (a button in the Inspector's panel toolbar ) used to grab a color from the page ([https://bugzilla.mozilla.org/show_bug.cgi?id=1568831 bug 1568831])