Users can create bookmark folders with no name

[alexwykoff]

Did you search for similar issues before submitting this one?
Yes

Describe the issue you encountered:
On the Bookmarks toolbar, if I choose to create a new folder, I do not have to provide a folder name. A folder with no name is created.

Expected behavior:
The system should prevent me from creating a folder with no name.

• Platform (Win7, 8, 10? macOS? Linux distro?):
  Tested on OS X
• Brave Version:
  Discovered in 0.11.5 RC1, but repro'd in 0.11.2. It's probably always been there.
• Steps to reproduce:
  1. Make sure the bookmarks toolbar is visible
  2. Right-click on the toolbar and select 'Add Folder...'
  3. Click Save
• Screenshot if needed:
  
• Any related issues: