Fix overflow for URL autocomplete on Windows

[bsclifton]

• 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). N/A
• Ran git rebase -i to squash commits (if needed).
• removes padding (not required after accepting Minor toolbar visual refinement suggestions #4400)
• includes hardcoded size of menubar in offset calculation

Fixes #4539

Auditors: @bbondy @luixxiul

screenshots

before padding removed (5px top and 5px left of URL bar)

after padding removed

new URL autocomplete size with menubar open

[bsclifton]

I tried to get a more approximate height using:
Number.parseInt(window.getComputedStyle(document.querySelector('.menubarContainer')).getPropertyValue('height', 30), but it returned the height of the entire window.

I'll look into this more tomorrow (it can be fixed in a follow up 😄)

[bbondy]

++