Investigate UX impact of removing window titles

Investigate UX issue of removing window titles in Tor for GNOME and KDE and possibly Windows.

Background: #41988

Design estimate:

• Complexity: medium (3 days)
  • Create an option in about:preferences#privacy that toggles the titles from being shown on the window.
  • Decide if the option should be enabled by default. Preliminary findings show that it will have minimal impact to usability, but perhaps more research and discussion is warranted.
  • Create copy for help pages.
• Uncertainty level: moderate (1.5)
  • This is a small, but far reaching change especially when releasing to multiple platforms. I imagine there's some uncertainty in this task.
• Total: 3-4.5 days