Fix: Fixed crash that would occur when adding a new tab

[hishitetsu]

I believe this happens when the view model (ViewModel) is replaced and the property within it (IsPageTypeNotHome) is changed at the same time. So I added a dedicated property that controls whether the selection/layout/sort buttons are displayed or not. This is the same mechanism that controls the preview button display.

Resolved / Related Issues

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  Closes Bug: Clicking new tab button crashes app #12826

Validation
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[yaira2]

LGTM