Description of the new feature/enhancement

It would be great to be able to hide both titlebar and tabs by default (like focus mode currently does) but show tabs as soon as as they are 2 or more.

Proposed technical implementation details (optional)

Add a setting, disabled by default, which does the following when enabled:

• Hides the titlebar
• If there is one tab, hides it

It may be a good idea to see if this setting could instead be based on the values of alwaysShowTabs, showTabsInTitlebar, showTerminalTitleInTitlebar

Screenshots

Here is the desired behaviour:

With one tab:

With multiple tabs: