Add support for native titlebars in Audacity 4.x on Windows

### Problem to be solved

Have the option of having the native titlebar on Windows like it was on Audacity 3.x and prior.

### Your idea

With Audacity 4 on Windows, the title bar is fused with the menu bar, which no longer displays the name of the first track that was imported or opened. It offers smaller caption buttons than standard windows and lacks the customization options that Windows provides. My idea is to give Windows users the ability to restore the Windows title bar instead of the custom implementation, as it was in Audacity 3.

### Prior art

Audacity 3:

Audacity 4 currently:

My proposal:

My other proposal which would be to re implement how the menu bar was themed on audacity 3 which I do not think it is feasible on QT but might as well propose it:
**(Note: This is not Windows 7 but Windows 10 themed to look like Windows 7)**

Audacity 3:

My proposal:

### Additional context

_No response_