"Show only favicon" option should include folders on bookmark bar

[luixxiul]

Describe the issue you encountered: As empty title for bookmark folders were disabled with #3347 and #3412, the option "Show only favicon" should hide the folder title too.

Expected behavior:

• Platform (Win7, 8, 10? macOS? Linux distro?): Windows 10 32 bit
• Brave Version: 0.11.6 Beta6
• Steps to reproduce:
  1. Create a bookmark folder on the bookmark toolbar
  2. Open about:preferences and enable the option Show only favicon
• Screenshot if needed:
• Any related issues: Bookmark folder names should contain visible text #3347, Do not let empty spaced bookmark title fixes #3347 #3412