Allow to show editor actions in title bar even when tabs are visible

[bpasero]

The new support for showing editor actions in the title is very nice, but limited to when tabs are disabled. I suggest to make this a setting that users can turn on irrespective of how tabs are displayed.

This could possibly help for:

• Tab wrap - implement different presentation so that tabs don't jump around (editor actions, decorations, dirty state) #115136
• Editor toolbar actions jump causes miss click #196361

[gjsjohnmurray]

Presumably related to #196609

[benibenj]

Closing as this has been in insiders for 2 weeks. I also added toggling the setting in the title bar when tabs are hidden. (#198494)

[benibenj]

verification-steps:

1. Start with: workbench.editor.showTabs: multiple, window.titleBarStyle: custom
2. open tab bar context menu, should see Editor Actions Position submenu
3. press titleBar, see how the actions move to the title bar and layout actions from title bar move to overflow menu
4. open tab bar context menu, should see Tab Bar submenu
5. press none, tab bar disappears and editor actions still be in title bar
6. open context menu of title bar, should see toggled Editor Actions entry (only can be seen when tab bar is hidden)
7. toggle Editor Actions -> editor actions hide. toggle again -> editor actions show again

[gjsjohnmurray]

Looking great, except that until #198494 lands in the next Insiders build steps 6 and 7 aren't possible.