[sailfish-browser] Do not load home page when first usage is not done

Key changes:
- Hide first usage overlay immediately when tabs icon is clicked
- Do not allow screen capturing when web container is invisible (first usage not done)
- Hide status bar when first usage not done
   - clear first time usage
   - xdg-open link A
   - close browser
   - start browser from application grid
   - Link A is loaded but is invisible