Buttons to add bookmark / bookmark folder in about:bookmarks

[luixxiul]

Expected behavior: On the left row of the restyled bookmark manager it should be possible to add a bookmark folder on the top level besides Bookmark toolbar and Other Bookmarks. For now you can just create one under Bookmark Toolbar.

• Platform (Win7, 8, 10? macOS? Linux distro?): OS X
• Brave Version: https://github.com/brave/browser-laptop/tree/43c0100c617b289da846d218a231d7a837f35aa7
• Steps to reproduce:
  1. Open about:bookmarks
  2. Show the context menu on the left row
  3. Select "Add Folder"
• Screenshot if needed:

- Any related issues:

[bsclifton]

From the original issue:
#4562

Here's the mockup image for the new about:bookmarks screen:

[bsclifton]

@luixxiul I renamed the issue- did I understand it correctly? ex: having the folder with the + will solve this issue?

[luixxiul]

Also creating a folder directly from context menu like doing so on Windows Explorer would be nice; by doing a right click a folder is created and you can change the title from "Untitled" at the same time. Is this clear?

[bsclifton]

@luixxiul great idea 😄

[bsclifton]

@bradleyrichter there doesn't appear to be a font-awesome icon for new folder (they do have an open issue to add one, but it's been open for a while FortAwesome/Font-Awesome#3752)

Do you have an SVG we can use for this? Also, I same with the star which has the + (in the title column). Thanks 😄

[bsclifton]

Awesome, just saw the icon as one of the SVGs in #4852

I'll use a temporary one for the time being