Horizontal panel in browser subapp

As a user I want to see most important stats about my content in my browser overview so i don't need to switch to other tools.

AC:

• Add expandable panel above title row of grid/tree view in browser subapp
• Add metrics icon button next to the view icons to toggle visibility of the panel
  • white icon bg = hide panel (default)
  • grey icon bg = show panel
• When resizing browser window the panel width is flexible according to the grid width

To demo the above:

• Open assets app
• Show 2 buttons before "view option" buttons above grid (cat / dog)
• Horizontal panel is collapsed
• Click on cat button, button bg is grey (active), panel expands, show cat image in panel
  • Click on cat button again, panel collapses, button bg is white
• Click on dog button, button bg is grey (active), panel expands, show dog image in panel
  • Click on dog button again, panel collapses, button bg is white
• Toggle btw cat and dog button, toggles 2 images