Closing the Details window last causes loss of Session history

[philrz]

Repro is with Zui Insiders v1.0.2-1, which is based on Zui commit f2bce04.

As pointed out in #2743 (review), the fix to #2730 reveals a second order issue. As shown in the attached video, if the Search window is closed first and then the Details window after, the Session history is gone when the app is relaunched.

Repro.mp4

[philrz]

Verified in Zui Insiders 1.17.1-insiders.11 which is based on Zui commit d3a0402.

As shown in the attached video, now if the Detail window is closed last, the History of the previous Query Session can still be found and restored from under the new Sessions tab.

Verify.mp4

Thanks @jameskerr!