Restore disabled dragging and context menu for Bookmarks Bar on Windows

[petemill]

Previously it was enough to not add 'drag' to the bookmarks bar on Windows, but now that it is added at a higher level in the DOM (so that dragging works in the margin between the bars) via #10512, we have to explicitly set it to 'no-drag' on each child.

Fix #11728

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed. (Ask a Brave employee to help if you cannot access this document.)

Test Plan

Windows only

1. Turn on bookmarks bar
2. Add a bookmark to enable bookmark toolbar
3. Right click anywhere on the tool bar

Expected

• On a link / folder, shows relevant context menu, not system window context menu
• On an empty space, shows 'add folder' context menu, not system window context menu

Reviewer Checklist:

• Request a security/privacy review as needed if one was not already requested.

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run individually or as a suite ref
• New files have MPL2 license header

[bsclifton]

Works beautifully! 😄 👍

[bsclifton]

master c576b37

@petemill can you help me cherry-pick this one into 0.21.x and 0.20.x? Getting some conflicts and want to make sure it's done properly 😄

[petemill]

@bsclifton I'll take a look!

[petemill]

0.21.x 565c4a9
0.20.x 54f89bc